Hey everybody, Dr. O here. This video we're going to talk about the different types of muscle contractions. So we always talk about lifting weights, but we never talk about the fact that lots of muscle contractions lead to no lifting or no movement at all. And also we have to lower the weights that we lifted. So we're going to talk about these different types. So real quickly, all muscle contractions that can be broken down into isometric, isotonic, then there is also something called isokinetic, but that takes specialized equipment like Cybex machines. So isometric is going to mean same length. So muscle is going to contract, but it's not going to change in length, meaning it's not going to get longer or shorter. So there's not going to be any movement. Isotonic means same tension, same tone. These are going to be the type of muscle contractions where there is a change in length. And we'll look at how we break those apart, whether the muscle is getting shorter or longer. Just because I brought it up, isokinetic means same speed. So there are special equipment that will allow you to lift weights at a set speed. So when you're feeling really strong, you'll be lifting heavier weights at that speed. As you weaken, the weights will get lighter. And like I mentioned, it takes specialized equipment to do that. So let's not worry about that. So let's jump in here. And first we'll talk about isometric contractions. These are going to be contractions where there's no movement. So when you think again, when you think of contractions, you probably do think of movements, but imagine how many muscles have to contract. Like just me sitting here, if you standing up, right, it would take a couple of hundred muscles easily for you to stand still, right? So think about all your postural muscles. That's what I think of with isometric contractions. Now there are, like if I take my hands and I press them together here, this is an isometric contraction. I'm contracting the same muscles that I would in my chest and my arms is if I was doing a push-up. But since there's no movement, it's an isometric contraction. But generally think of your postural muscles and how much muscle contraction it takes to sit or stand still. And you would see that for most people, unless you're very physically active, isometric contractions would be the most common type of contractions that you would have, especially if you were standing a lot. So that is your isometric contractions where muscle contracts but does not change in length, so there is no movement. So next we have, there are two types of isotonic contractions. So you have to know these terms as well. And that would be concentric contractions, which you see right here. And the next slide will show you eccentric contractions. So both of them, there is a change in muscle length, so there is going to be movement. So make sure you note this, concentric contractions, muscles contract and get shorter, eccentric contractions, muscles contract and get longer. So here let's look at the concentric contraction first. This would be called the lifting phase of a movement. So if the muscles are contracting and getting shorter, it's because you're like in this situation, this man is lifting the weights, he's curling, he's doing the bicep curls, he's picking the weight up, so it's called the lifting phase. Same thing as if you're doing a push-up when you're pushing off the floor, that would be concentric contractions. So these are also called positives. So the lifting phase of a movement and the positive phase of a movement are two terms you might see when someone's talking about concentric contractions. So muscles are contracting and getting shorter. When we talk about the action of a muscle, what it actually does, we usually are talking about a concentric contraction. The last type then we have are the eccentric contractions where while a muscle is contracting, it's getting longer. So this would be called the lowering phase of a movement. Notice how this guy here in the picture is putting the weight down. He's lowering the weight back to his side. Or if you're doing push-ups, as you lower yourself to the floor, that would be eccentric contractions. So this is called the lowering phase of the movement and then also this is called negatives. So if you spend much time in the gym, there are negatives. For example, if you want to use negative or eccentric contractions when you're lifting weights, you might have, let's say you're doing a bench press, you might have spotters that actually help you lift the weight and you just lower it on your own. Now the reason you do that is because eccentric muscle contractions are where most of the muscle damage comes from. I think that makes sense. The muscles are while they're contracting, they're being pulled apart. So every so often you might want to do this, but this could lead to a lot of muscle damage, but if you're trying to get bigger and stronger and more explosive muscle damage and the repair from that damage is actually what you need. So, all right, so just to review, we have the isometric contraction. There's no change in muscle length, so no movement. Think postural muscles. And then we have the two types of isotonic contractions with a con-center contraction and muscles contracting while getting shorter. So you're lifting a weight or doing a positive movement. E-center contractions, muscles are contracting while getting longer. So you're lowering a weight or doing a negative movement. So those are all the different types of muscle contractions that you need to know. Have a wonderful day. Be blessed.


Hi, you guys.  Thank you so much. I love gifts I love things that people send me a lot of people have their own businesses and They're just so nice to gift me and I truly appreciate that this comes from one of one of my viewers and I wanted to say thank you so much You know who you are She has her own Line of eyelashes. I'm like what you go girl. Okay, so She sent me these beautiful lashes her the name of her company is iconic rose and This is the back of These beautiful lashes the name of these lashes are hot girl Okay, hot girl is it upside down? Yes hot girl. Okay, so she has her website I'm gonna link it below if you guys want to go look at her website and purchase some lashes as well There's her website at the bottom. I'm gonna also put in the description box, but There are two that she sent me so here are the other ones. Oh my god, look at those lashes, okay These are called temptress And this is gorgeous from day to night now I believe she sells meek lashes and then she sells the other lashes that are not made of meek So it's you have a choice of which ones that you want you can mix and match and get both I know a lot of people like the look of meek lashes and They're very Plush, so I've never tried meek lashes you guys, but guess what I'm getting ready to try so I don't which one which one is meek I'm not sure Okay, but they're handcrafted luxury lashes These are not those cheap ones that you buy at the beauty supply ladies, okay These are something that you're gonna spend a little money on okay, but they're gonna look good. Okay, you think Beyonce Kim Kardashian Nicki Minaj Rihanna, do you think they should they get their lashes from the Dollar Tree now? They buy They buy lashes that are quality. Okay, so that's how they look. That's how it comes Now I don't these are these are very natural looking but they're long Okay, I like those now those would probably be like a nice, you know natural more natural look and Those are hot girl Okay, now these would probably be more for a More dramatic look these are temptress so I'm going to the grocery store. I Need to put on the other ones But I'm gonna try them both on for you guys, but I'm probably gonna end up wearing The hot girl today, so let's try let's try these on first Okay So what I like to do Take them out of the package Okay, they look like this There's a little bit of glue still stuck on it. You can peel that off or leave it on for extra stick I don't know but I'm gonna be using some lash glue by I Don't know it's called strip last at strip lash adhesive with aloe. I Have no idea But that's I think I got this from Walgreens or something It's one of those ones that you can actually paint on so it's less messy and get a really good application of glue on there without Dripping it everywhere. So you kind of let this dry for a few minutes. Well, maybe one one minute I blow my to have to speak the brothers y'all Okay, so I feel like this is going to be on my Left eye. So let's let's get started. Okay. I'm a little mirror here I'm gonna try to put this on without dropping it. I Usually don't use tweezers, but I have some just in case I need to kind of work with them Work it around. Okay, these are very natural and then the band is very thin You're not gonna be able to see it like sticking up. I feel Like some of the store-bought lashes I'm gonna use a little baby tweezers to kind of pull it in place Like put poke it down Okay, wow Wow Okay, wow, these look really natural these look like if you were to go get your lashes done at the salon That's what it looks like. It looks like your own lash because the band is so thin Look at that. I'm gonna zoom in Look at that. Isn't that look natural like? Doesn't that look very natural? I don't even have like any Eyeliner to cover that band because it's so thin. You don't even need that. Look at that ladies Okay, I'm gonna try on the other lash the more dramatic. I'm gonna try that one on this eye. So y'all Get ready. Okay So that's what The dramatic lashes are getting ready to put on this. I look like I need to peel the right one off for the right eye and Wow Okay, so that's what these look like. I'm getting ready to paint on Let me back up again. Yeah, I love having this zoom because I can zoom in and zoom out on you Okay, so let me paint the glue on this one Okay, I might want to wear these dramatic ones out. Y'all know I'm extra. Okay Let's see what these look like. I bet these are gonna be beautiful So these are Temptress the ones I'm trying on on the right eye. They're more dramatic and bold and supposed to give you like This dramatic lash. These are the meek ones. I feel Oh, we glue that stuck to the okay. Okay. Who is calling me on Facebook? I guess it was a mistake cuz okay, so I think it needs a little time to dry Um, sorry y'all, you know, oh My gosh, I love these. Okay. I'm in love with the mink lashes. Okay. I'm in love with the mink lashes Look at that. Okay. Now these are there the nice Natural subtle. I don't think these are mink. I these are the mink ones. Okay, so I like the mink ones Okay, these are good for like You know going out in the daytime going to the gym if you want lashes to the gym But these this is more my style. I already knew that I was gonna love these. Oh my gosh Okay, so I'm gonna link all the information below so you guys can go get your lashes Look how natural they look. You don't even I thought I was gonna have to put Eyeliner on to cover up that band, but you can't even see it Okay, I had my eyeliner and everything ready. I was gonna ready put it on but I need it. I Love these lashes. Okay. The band is so thin. You don't even need eyeliner. Just gotta Put them on right by your lash line and then bam, you're done. Okay I don't even wear lashes a lot, but these are so easy to put on so thin and they apply so easily I could actually wear these Without even feeling, you know, like I have on anything. They're actually very light.  It's the same amount of You know Weight on your eyelids. So I don't really feel a difference and if I would or to put on like three four coats of mascara I didn't get this look, you know, not even close to this look but try to get it So, oh my god, I'm in love I'm gonna go throw the other mink ones on because I want to be extra today in the grocery store Let me fill that one. Look how easy they come off. Okay Thank you so much for sending me these I use ya, I Love them.  Okay, so I'm gonna put on the other one now because Like I said, these are awesome and I will Get these two thumbs up. Y'all know that three thumbs if I had a third hand. I love these And also, you know ladies, it's you know, you get a good glue and you're good Don't get don't get sloppy glue because a lot of times people make Applying lashes harder than what it is get you a nice glue like that that you can paint it on really really thin and Then have it dry clear Okay, don't make stuff more complicated than what it is you get the good products that are gonna make Your lash application easy Okay, see that was quick. That was you know It's still not on there holding that hold it on there for a few seconds to make it stick One two three There we go Now if you want a lot like curl your lashes it with these lashes and then put mascara on all the lashes together To kind of make them look uniform Mine already look like, you know There you can't really see them So I feel like I don't really have to do all of that but some people do So, you know, I know you can wash these lashes and dry them and reuse them So if you want to put mascara on them, you totally can't I don't think I need to I Think they're enough Enough for not needing these lashes. I mean the mascara just the lashes are quite enough Okay, so this is the finished results of Temptress, okay, and these again are by Iconic Rose Y'all go check them out Online and support Support support support. She's a young lady. She started her own business and you know She watches all of my channels. She's a she's my friend on Facebook and you know, I Just really want to promote people that are really adamant and passionate about their business Doing what they love instead of you know Working and you know being unhappy and things like that they take risks and you know, they need our support So let's support her Let's support her Everybody like needs to look beautiful, you know, you trying to catch a man trying to get a promotion at work You need these lashes Okay All right, I'll see y'all later. Bye


T. F. N. N. Headline News Update. Good afternoon, folks. Steve Rhodes coming to you live from the shores of partly cloudy Delray Beach, Florida. This is your 2 p.m. update. And as a 2 p.m. update, we've got a mixed bag out here. The mixed bag, as we'll see here momentarily, is the Dow is trading up 117 points while the S&P is off 5. The NASDAQ is off 51. The Russell's up 9. The Semi's up 11. The trainees are up 1. So we've got the old mixed bag out here. You've got gold is up a buck 50. Silver down 15 cents. Lights recruit up 65 pennies. Natural gas up 29 cents. Let's go take a look at our index ETF or our ETF charts out here. So we'll begin by looking at I've got to change panels out here. I believe we'll begin by taking a look in the upper left hand corner of the QQQ chart. Here what we see is a TD nine count top prices below the bottom of its profile and that suggests that the QQQs are making a move to the 368.79 level. That's the TD nine to breakout area. The spies, the chart next to it shows a TD nine count top and price may be targeting its breakout level 443.44. If that level fails, the next breakout area would be the target 439.88. Let's keep going across on the upper right. The XLK, a TD nine count top, a price is still above the top of its daily profile and that becomes the support area 155.41. The price closes below that 154.01 is the real strong support area. That's the center of its profile and that is the TD nine breakout level. The XLV, it has a roadsman to indicator top and price right now is testing the bottom of its profile. If price closes below this level, run 132 and change out here. That would signal move back to 127.64. Lower left Dow Jones industrials via the diamonds. What do we have? We've got an inside day. An inside day typically signals that the trend that was in place prior to the inside day will continue. Well, that's a downtrend and that could signal that the Dow diamonds are targeting their breakout level of 338.68. The Russell 2000, a TD nine count top, price fighting support right now at the bottom of its daily profile. The level to watch there is to 2075. You've got a hammer candle right now and that would be a Gertley by pattern that would form if this were 4 p.m. It's not 4 p.m. But watch for that. The XLF just consolidated with inside its daily profile, the XLC, the communication sector for the S&P 500, the TD nine count top, price may pull back to the 82 84 level. Folks, they do it for the power trading hour. I'll see you back here tomorrow at one o'clock. Take care. Have a great day. The reality is that navigating financial market


Welcome to the Endless Knot. In this special episode, we're joining team trees to try to plant 20 million trees. And so, since this is all about tree planting, let's see if we can find a family connection between trees and planting via etymology. Tree planting, for the purpose of reforestation, is one of the strategies to mitigate climate change because trees take carbon dioxide, a greenhouse gas, out of the atmosphere, converting it into oxygen and trapping the carbon in the form of biomass. So the idea is to create or recreate forests. The word forest literally means outdoors, coming from Latin forests outside, from the Proto-Indo-European root d'ware, meaning door, also the source of the English word door. It probably came to refer to a bunch of trees from the medieval Latin phrase forestem silvam, the outside woods. Referring to forest outside of the fenced-off woodland that was reserved for royalty, initially in this case Charlemagne. You weren't allowed to hunt in his private woods. That Latin word silva, meaning tree woodland, by the way, probably comes from the Proto-Indo-European root widhu, tree wood, which is also, through the Germanic branch, the source of Old English Wudu and Modern English Wood. The main Latin word for tree, arbor, from which we get arbor day and arboraculture, comes ultimately from the root ered, high, also the source of the words arduous and orthodontist. So unlike wood and silva, the sense development of arbor is figurative. As for the word tree itself, it also comes to refer to trees in a figurative way. Tree from Old English trow comes ultimately from the Proto-Indo-European root deru, meaning to be firm, solid, steadfast. And what is a tree if not firm, solid, and steadfast? And that's why this root led to a number of words having to do with trees or objects made of wood, including trough, a wooden vessel, dryad, a Greek mythological tree nymph, druid, a Celtic religious figure connected with tree worship, and dendrochronology, dating tree rings, which is one way of tracking climate change. But there are also a number of words in English that are connected to the literal meaning of deru, such as trousse, a kind of solid pledge, trust, a solid or firm confidence you might have in someone, and trist, originally meaning a place where one waits trustingly, but now used in the sense of a lover's trist, which ironically might indicate an extramarital affair. But another important word, or really two words now, that we get from this root are truth and trough. In Old English, these were the same word, trough, which had a somewhat broader range of senses. Faith, loyalty, truth, think of Superman's truth justice in the American way. Trough now has the specific sense of a pledge, and is mainly known from the specific contacts of plighting one's trough and betrothal, in other words, an engagement. So a betrothal is a pledge, and this is also etymologically true of an engagement, which comes from old French engagerie, to pledge engage, through the Germanic Frankish language, ultimately from Proto-Indo-European wad, meaning a pledge to pledge, from which we also get the words wed and wedding. Marriage and marry come through old French from Latin maritare, to wed, marry, given marriage, from maritus, married man, husband, which may come from the Proto-Indo-European root mari, young man or young woman. Marriage is also known as wedlock, and the lock part, by the way, is not connected to the word lock, but is instead a suffix denoting an activity from Proto-Indo-European leg to leap tremble, also the source of the word lark, though I would suggest that marriage is more than a lark. And matrimony, which is not related to marry, but instead comes from Latin matrimonium, from the Latin word mater, mother, thus indicating the primary purpose of marriage, for the Romans at least. Now given that producing legitimate offspring has historically been one of the most important aspects of marriage, typically cultures have rules about marrying outside of one's own kin group or other social group, what's called exogamy, to avoid inbreeding, though some cultures have rules about the opposite, endogamy, in which one has to marry within one's social group, such as within one's own ethnic group, caste or religion. Now the degree of closeness in terms of an exogamous marriage differs from culture to culture, and indeed different cultures have different systems of kinship terminology. Not only for this purpose, but also to reflect different social roles relatives are expected to play within the family structure of any given culture. The anthropologist Lewis Henry Morgan identified six distinct patterns of kinship terminologies. For instance, in English-speaking societies there is no distinction between aunts and uncles on the mother side or the father side, and the word cousin is even broader, being applied to any gender, but other cultures have finer distinctions than those, and conversely, other systems use the terms equivalent to brother and sister to include cousins as well. And rules about exogamy can cover not only what we might consider close family, but also larger kin groups, clans, and even whole tribes. In some cases, linguistic exogamy is required in which one must marry a speaker of a different language. The word family comes from Latin familia, which included not only the blood relations within a household, but also the slaves, freedmen, and other members of that household. And in fact, the word familia comes from familus, serving serviceable, from the Proto-Indo-European root de, to set put. The word kin is a Germanic word from Old English kyn, which could refer not only to one's family or relatives, but also a whole people, and comes ultimately from the Proto-Indo-European root genna, to give birth, begat, which is also the source of the word genz, which is the Latin word to refer to one's blood relations, though only through the male line. As for tribe, it comes from Latin tribus, which originally referred to the original three tribes of Rome, the tites, the romnes, and the lucares, coming ultimately from the same root as the word three, Proto-Indo-European tray tree, plus the root of the verb to be, beua, though a connection with the root treb, dwelling, has also been suggested. Related to the word tribus is tribunus, originally the head of a tribe, from which we get the word tribune, and tribura, to give out amongst the tribes, from which we get the words contribute, distribute, retribution, and tribute. And finally, the word clan comes unsurprisingly from Gaelic. Scott's Gaelic clan originally meant offspring, coming to refer in the Highlands to a tribe holding land in common under the leadership of a chieftain. Now the Gaudelic branch of Celtic had no initial puh sound, so what was originally a puh became Gaelic cuh, in the word clan. This word was a borrowing from Latin planta, in the sense of an offshoot, from which of course we get the word plant, and indeed the word plant in non-Gaudelic Middle Welsh means children. Latin planta means sprout, shoot, twig, graft, but also the sole of the foot, because when planting you press down with the sole of your foot. Planta comes from Proto-Indo-European plat to spread, also the source of the word flat, ultimately from the root pella, flat to spread. Also the source of the word planet, through Greek planesthy, to wander, because the planets were the esteris planetae, the wandering stars. So since we have only one planet to live on, we better put our foot down and act as one true global family and make a pledge to plant some trees. If you'd like to donate, head over to teamtrees.org where $1 plants one tree. Think of your family trees. If you've enjoyed these etymological explorations and cultural connections, please subscribe and click the little bell to be notified of every new episode. And check out our Patreon where you can make a contribution to help me make more videos. I'm at alliterative on Twitter and you can visit our website alliterative.net for more language and connections in the podcast, blog, and more.


Good afternoon. This is the public meeting for Brentwood is to road area water and through improvement project. And this is the agenda for this meeting. I am going to provide you project team introduction. I'll provide you project overview. We'll talk about the project area. Some of the frequently asked questions and then the project timeline. My name is Pratima and I'm the project manager for this project and I'm with city of water department. My phone number is eight one seven three nine two six one four nine. An email is Pratima at photo takes us dot com different. Barnard is the city inspector for this project. He is with transportation and public works department. His phone number is eight one seven eight nine seven three zero eight three. An email is Stephen that Barnard at photo takes us dot com. Great takes utilities is the contractor for this project and Greg Hidal is the representative from critics. A and a consultant is the engineering firm who designed these projects and Alex sir is the project manager with any project overview. Agility water and sewer means will be replaced in an area bound by Brentwood is to road to the north. East loop eight twenty to the east Normandy road to the south and Carl straight to the west. This capital improvement project is in city council district eleven and five construction will impact West Middlebrook neighborhood association neighborhood of East Fort Worth central Middlebrook Eastern Hills. And Brentwood Oak Hill and this is one of the project area and the black line you can see over here. Is where we are going to replace water and sewer line. The first one is called street. We are going to replace both water and sewer in Carl street. And the limits of replacement is from Normandy road to major street. The second line is on a good terrace. We are going to replace both water and sewer on Azure terrace as well. And the limits of replacement is from Normandy road to Kimball Street. This construction will impact city council district eleven West Middlebrook neighborhood association central Middlebrook neighborhood association and the neighborhoods of East Fort Worth. In the same area there is another street to hold the street where we are going to replace the water and sewer both and the limits of replacement is from Kimball Street to Brentwood here. And on the brain to this year itself we are going to replace the water line and the limits of replacement is from whole street to selling stride and this construction will impact central Middlebrook neighborhood association and neighborhoods of East Fort Worth. This is another area in this project. The first one is rocket code. There's a small section over here. We are going to replace water line in this street and the limits of replacement is from Charlotte straight to the cul-de-sac. This construction will impact Eastern Hills neighborhood association and the neighborhoods of East Fort Worth. Another street in the same area is Charlotte street and we are going to replace water and sewer line in the side of the street and the limits of replacement is from rocket core to the Blu-Ritz drive. In the same area there is a small section over here in the easement where we are going to replace the sewer line and that construction also impacts Eastern Hills neighborhood association. This is another area where we are actually extending water lines to complete the loops. The first section is on the Brentwood street road and the second section is on the Brentwood drive intersection over here. Two sections of water line extension is in City Council District 5 and this construction will impact Brentwood, Oak Hills neighborhood association and neighborhoods of East Fort Worth. Some of the landmarks near our project areas, Interstate 30 to the north, Oakland Lake Park and Postic Lake to the west, Middlebrook Middle School to the south and Middlebrook Golf Course to the east. Now we will discuss some of the frequently asked questions. The first one is why are we doing this project? City of Fort Worth prioritize is replacing up the water and sewer lines that have high risk of failure. How we determine high risk of failure is based on several available data such as water main break history, leak history, CCTV inspection data for the sewer line, ease of the line, line material. If the line has laid services or if the line is a cast iron line, which issue is specific to this project? This project was created as a part of water cash initiative to reduce the amount of water breaks. Fort Worth water management has committed to replacing a minimum of 20 miles of cash iron type each year. Currently, there are approximately 100 miles of cash on remains at various stages of the design for the replacement in the fiscal year 2023 and beyond, which is straight in this project have cash iron water line. This project will replace cash iron water line in Carl Street, Ajo Terrace, Holt Street, Brentwood Street Road, Rockhill Court and Charlotte Street. How will we know construction is starting? If you leave in the area impacted by this construction, you will get two door hangers. The first one says construction starts in seven days and it looks like this. And the second one says construction starts tomorrow and it looked like this. The door hanger also includes the city inspectors business part with his or her contact information in case you need to contact them. What are the construction hours? The regular construction hours are 7 a.m. to 6 p.m. Monday to Friday. And if requested by the contractor and if it is approved, they can work on the Saturdays from 9 a.m. to 4 to 5 p.m. There will not be any construction on Sundays. Contractor will also not work on nine city holidays, which are Thanksgiving, day after Thanksgiving, Christmas, New Year's Day, Martin Luther King Day, Memorial Day, Juneteenth, Independence Day and the Labor Day. Will there be lane closure during construction? One traffic lane will be closed on Carl Street, North Isotera, Old Street, Brentwood Street, Rock Hill Court and Charlotte Street when water and sewer lines are replaced and the trench is being repaired. The lane closure sign will be posted to alert the motorist. What happens if my property is damaged? The contractor will take pictures and videos of the property before breaking ground. We also encourage property owners to take pictures and video with a data stamp of their property prior to construction. Damage resulting from the contractor's activity during construction is the responsibility of the contractor. Will construction affect my irrigation system? The contractor has to cap irrigation lines before construction starts. The contractor will ask property owners to turn on their irrigation system so the sprinkler head can be located and flied. The contractor will replace capped or damaged irrigation system if they were damaged as a result of this construction. Will our water be turned off? Water will be turned off for 15 to 30 minutes when service is transferred from the existing line to the temporary water line and then again from the temporary water line to the newly installed line. These switchovers are done during the daytime. The contractor will knock on the door and let the customer know when the water will be turned off. The transfer typically takes about 30 minutes per house or business. How does the temporary water line impact my home and water bill? The temporary water line ensures that you are not without water during construction. In the summer months the continuous flow keeps the water from becoming as tangent in the upper ground line. During the winter months water must be continually flowing through the temporary line to keep the line from freezing. Customers should also keep their faucet dripping. The bill for your water uses while you are on the temporary line is based on the average of the previous month's uses. Will we have access to our driveway during construction? City inspector and the contractor will work with businesses and residences that need driveway access during active construction hours. And again those active construction hours are 7 a.m. to 6 p.m. Monday to Friday and if requested by the contractor 9 to 4 or 5 p.m. on Saturdays. Will you need access to our property? Photos water will abandon the sewer line in the alleyway between Carl's Street and Azure Chairs. Therefore we'll need to reroute the sewer services on the following addresses to the Carl's Street. And the addresses are 1825 Carl's Street, 1817 Carl's Street, 1809 Carl's Street, 1805 Carl's Street, 1801 Carl's Street, 1733 Carl's Street, 1729 Carl's Street, 1725 Carl's Street, 1721 Carl's Street and 1717 Carl's Street. Do we have to grant access to our property? With the exception of some properties on the Carl's Street this construction is in public right away and is in utility easement. If photos water needs access to your property we'll contact you before accessing your property. For those on the previously mentioned Carl's Street properties the contractor predicts utilities will bring temporary right of interlagers to those property owners. The Carl's Street property owners will have to sign the temporary right of interlagers. Without the signed temporary right of interlager the contractor will not be able to relocate the sewer services. Will our sewer service be interrupted? Any two sewer services will not be interrupted. New sewer cleanouts will be installed at the property line. The sewer cleanout provides crews easy access if there is a backup or a blockage. Will the city's trash truck will be able to pick up night trash and recycling during construction?  If you see water running down the street do not turn it off. Before we can connect your service to the new water line we have to flush the line. The water flow from the from flushing the line will be continuous until the inspector gets the samples for that day. You will be connected to the new water main after two consecutive samples pass the vector logical tip. When it is time to sample the water flowing through the new water main the contractor will place traffic cones around the valve to prevent anyone from parking over the valve. Do not move the cone, do not pass over the cone and do not turn off the water valve. Now the timeline for construction. The construction will start in December 4, 2023 and the project is estimated to complete in summer of 2025. The contractor will start on Cald Street, North Asia Street and North Asia Terrace and whole street first. Generally the sewer main is installed first and then the water main is installed when the street is getting both water and sewer replaced. That street will be repaved with asphalt after the water sewer replacement. If you are interested to get more information about this project you can go to the webpage www.phototixus.gov and tag the project number 103381-2 and you can go to the bottom of that page and click on subscribe to this page to get more updates about this project. The project map, project summary, frequently asked questions and the power point will also be linked to this project page. If you have any water or sewer related emergency or non-emergency issues you can call the number<PHONE_NUMBER> and select option one for the emergency issues. It is a 24-hour service and for non-emergency issues as well you can call the same number. You can also download my AFW app from the Apple Store or Google Play. You can report sewer overflows, leaks and water main breaks missing or broken meter leaks, water paced, water violation, no water service, water pressure issues and any other water sewer related issues through the app as well. Again, my name is Pratima Podyal and I'm the project manager for this project. My phone number is<PHONE_NUMBER>. Email is Pratima.podyal at phototixus.gov. Stefan Barnard is the city inspector for the project. His phone number is<PHONE_NUMBER> and email is stefan. Barnard at phototixus.gov. With that, this presentation is complete. Thank you.


Okay, so now do we go to interactive jobs? Yeah, let's do it. So now we are putting the sauna, like now we're hitting the sauna, now we're like getting somewhere. So this is the first, now we're actually starting to do something in the classes. So far, we just like unpacked our stuff, we have our stuff stored somewhere in the work directory, we have put stuff in the cupboards, we have organized, like we are ready to stay at this place, but now we actually want to do something there. So now we have connected there, we have found some firewood applications, we have found something that we need for our stuff. We have put our belongings to the proper places and now we want to run something. Yeah, so I guess first we need to talk about what Slurm is. So how would you describe that and why is it the most important concept here? Yeah, so basically what we, on day one we describe the cluster as like it's a collection of nodes and the login node. And there's hundreds of people using the same system at the same time. So if you think about like you have a computer at your home and you want hundreds of people working on the same computer, that wouldn't really work because there's only one keyboard and stuff like that. And the Slurm like helps this kind of a situation. So basically the Slurm manages all of the different tasks that are required from it. And it allocates resources for these tasks, for these jobs as they are called. And they are run then on the compute nodes. So basically the Slurm is like a very good, like what's it called in the restaurant like server, like who arranges, yeah. Yeah. Host or mater D or something like that. Yeah, yeah, yeah. Yeah, mater D who arranges like tables for your group. Like you come with a, you have a job that requires certain resources, certain placement on a table or something. Like they have certain requirements for their night in the restaurant. And this very good host manages to organize everybody at the proper places so that the restaurant is as full as possible constantly. And this is basically what the Slurm does. It's a queue manager that basically manages like all of our jobs that we submit. They end up to this queue and the queue manager will then arrange resources for these jobs. Right. So then what are the, so what's our interface to this? Like what's the part that we need to know when trying to run something? Yeah, like in the list that we currently have visible here, there's very good like examples of stuff we need to know. So the host, in order to get like what you, the current correct seating, the host needs to know how many party people are in the party and how long they're going to be dining there. So these would be, they represent like how many CPUs your job needs, how much memory does your job need, how long is the job going to be running. And then the host knows that okay, like this table will be reserved from this time onwards, but in the meantime you can sit here because your dining time is short enough that you can finish up before the next people arrive. So then once you, what you do, usually you use these S-interactive, S-run or S-batch commands to ask for these allocations. And then you're giving a number that basically tells what is your ID, like what is your reservation number, and then you are given the correct seating. And after that you can ask the host like am I currently, what is my situation? Am I allowed to run? What is what is happening? And then afterwards, well, you get, you can look at what happened, like how long did the actual job runtime take and stuff like that afterwards. So what happens if you really have no idea what these parameters are? Yeah, so the first thing is that you can first try just running something in the queue without setting these parameters at all. So basically if you have something, for example, here in the example, do you actually want to try and run this example? Yeah, sure. So let's see, here I am, so I am on Triton. Yes. Yes, so maybe I should make sure both are visible. Yes, that would be good. So the example is a very simple Python script. It just prints while it's running this command in Python. So we want to run this. Yeah, and the easiest way to test how it would run in the queue is to just add a run at the start. So what the s run means, yes, like that, what the s run means is that it basically, at that point, Slurm like understands that, okay, this one, this will be run in the queue and whatever comes afterwards is what will be run. So it will, like it says here, it will put the task into the queue and it's waiting for resources. And then once the resources are available, it will run the command. So in this case, because we are asking to print what is the name of the machine, it will, right now, when you see that it's been allocated resources, it will say that it ran on this CSL 46 machine. So it ran on a separate system. So it was allocated resources and then it got the resources and it ran. It ran with our default resources that are like 500 megabytes of memory and hour of runtime. But like in the example in the web page, you can specify these resources yourself. So let's say we want to add 100 megabytes and let's say, because it's very fast, let's say 10 minutes of runtime if you want to put. So is this 10 minutes or 10 hours? Well, it's hard to tell. So I would rather put two zeros at the front so that you know what it is. So that way it's like a universal clock. Otherwise, it's very hard to tell. And you can see that in the memory, there's like 100 and capital M. So you can put also gigabytes there with the G, but it's megabytes. You want to look at Slurm Q? Yeah, we can look at the Slurm Q. Well, we can do the monitoring later on. You can look at what's happening in the Q with this Slurm Q and Slurm... Well, these commands, but at this point it's not... We'll talk about monitoring in detail a bit later on. So it's not currently that important. But that will tell you what is the Q status. That is all the specific, I think. So other sites, there's a different command. We'll talk about that later. But okay, so there was good questions there in the HackMD of how do you know the resources of your job? And I usually say it like, if you have a computer, like let's say a laptop, and it's something and it takes like 15 minutes to run on your laptop. Well, you might expect it takes 15 minutes to run on the cluster as well, right? It's only natural that there are both computers. It should work pretty much the same. And that's usually the case. It depends, but usually I would guess something that is similar to, well, how it used to run. But if you're unsure, and anyways, you should put some leeway there. So put maybe like of the order of the job at runtime. So let's say your job takes an hour. I would put maybe two hours. So it has leeway to go above the hour. Like starting on your computer. Like your computer might have 16 gigabytes of memory. So start with that. Yeah. Same with the memory. Like put something like your computer might have 16 gigabytes of memory and the program runs. So you know that okay, maybe I'll put 16 gigabytes. We'll talk about how you can monitor these after the fact. Like how do you, how can you see what is the, how much it actually used after the program has run. But first you need to give it some ballpark. If you aim too low that the job is killed. So that happens when your allocations are like too low. Then you know that okay, I will need to put higher. And usually it's this kind of like you first need to get like a feel for your program. So that you then can like set more or better limits that are more clear or like similar. Okay. So what's next? Yeah. Let's talk about, so this job like over here when we run something, we run it on the login node. We run this S run something and then it ran on the node. But let's say we want to like, we run to test something out and we don't want to like constantly run the S run and wait in the queue. We just want to like have some, we just want to work like on a compute node for a while. Like for example, there was questions there that, let's say I want to like, yeah, I want to test my code, but I don't want to like mess up other people's stuff on the login node. That is usually a good idea to think about. So what you can do is you can set up this interactive job. So the interactive job basically like it allocates your job and it takes an SSH connection there. So you can, you basically get the terminal in that node. Does this work outside of Alto? I think that should work. We also, in Alto, we have this interactive command that basically you can just use to, like similarly to S run, you can run S interactive under requirements and you will get a terminal. So now you see that Richard, when the job was queued and was allocated, he's now, you can see on the left side of his command line, it says that he's running on a compute node. So basically he's running now like an interactive terminal in a compute node. And there he can run well what he wants without bothering other people in login node. Yeah. So this is a fairly simple way of getting like interactivity sources. Do I need to exit from here?  Does it say to you? Hmm. Maybe log out, try log out. But the shell did end. Hmm. Well, this is... Yeah, maybe the control B is the usual thing that I use. It might be that the... Could it be it's because this is not as interactive? Well, anyway. Try log out. Try log out. What happened? I will... ...lose the shell. Yeah. Yeah. Yeah. Okay. So can you check... Can you tell I have to get this locking thing set up again? Yeah. Okay. Can you check slurm queue? Is it still running? No. It stopped. Okay. Yeah. So what does this slurm queue do? This slurm queue... So this short hand for this SQ command that is like a bit more... Well, it gives information of what is happening in the queue. The slurm queue will tell what is the status of your jobs. We will be talking about these once we... More when we get to the non-interactive jobs. So the non-interactive jobs are jobs where you are not running something interactively. So maybe we should have a quick exercise of people trying to run, for example, the Python example. Okay. Let's see. Like five minutes or something if people can... You mean what we just did? Yeah. Yeah. People can run themselves. Which part? Well, let's say the S-run part. Yeah. Because that is the first step you're taking towards running stuff in the queue. So try running stuff in the queue and see if it works. Let's say five minutes on this. Okay. And if you have any problems, then we'll respond to the HackMD at the same time. Okay. So we're back. Hopefully you've been able to do that. So there's a lot of messages I see about different commands and partitions being different. Like in some computers it says use interactive, not S-run for interactive. In Alto you can also use S-interactive. There was a comment way above about is G-run the same as S-run? Or you need to use a different partition for interactive. And it's kind of a mess, isn't it? Yeah. I'd say that the G-run, most likely, like you're not working probably with a Slurm system. So all of the clusters in the world, they have some sort of like a queue manager. Like there are many of these like PBS, Slurm, Cray has their own. I can't remember all of them. But Slurm is the most popular, partly because it's free, but it's also very good. But so can't say if that's the same. But on other sites the interactive queue might not exist. So you might need to take the P flag out. We will go into detail what are those different flags when we go to the serial jobs. There's an interesting question here. If both Triton and my computer runs a program in the same one hour, what's the point of using Triton to run the program? I was thinking it should make it faster somehow. Yeah, that's actually a very good philosophical question. Like why would you use it? So the idea behind the cluster is that you can... something that would take your laptop, let's say, a full night's work of just wearing in the background of your apartment and making you sleep less well. Something like that can be put into a computer cluster and you can run it there and, well, you sleep well. And at the morning you can come back to the resources, come back to the results and see them. Or you can even run the same analysis, let's say, with multiple parameters, like separately, run multiple of these jobs so that suddenly you will get benefits. Like you can run multiple of them at the same time. Or you can either, if your program supports it, you can use the multiple CPUs. So when we are talking about what is improvement or making something faster, it doesn't necessarily... we are not talking about you waiting looking at the computer. We are talking about what makes it faster for you to get to the end goal. This is what... the XY kind of a problem. So the end goal is that you get, let's say you need to do a thousand simulations.  Or you need to stop the simulation while your laptop is doing the calculations or stop, like, while you're doing the Zoom call. So the idea is that you can offload a lot of this work to the cluster systems where you can run, let's say, multiple of these simulations at the same time. And there's basically like an army of little work people who will generate the results for you once you tell them what you want to be done. So it's like offloading the computation somewhere else. And that will reduce the overall runtime. Of course, some programs, they are faster. Of course, if you run multiple CPUs and stuff like that, they can also be faster like in real time. But in many cases, the situation is that what is like the faster for the whole project? And that is like something that you need to think like, if I would have 100 laptops, would I get this done faster? Because I could put one simulation running on each of these laptops. And of course, you don't want 100 laptops in your home. Like that's insane. And you couldn't even use them? Yeah, like who's going to like running the commands on every laptop? That's like so much work. It would become really laborious. But that is completely trivial to do in cluster. Like you just like we talked tomorrow about this array talks and you can immediately like run 100 simulations simultaneously. And it's like, it's not a biggie like in a cluster environment. And the thing is that like, like speed up and what is faster, it's not necessarily you shouldn't think about like clock time. You shouldn't, you should think about your work time. That is the most important thing. Like you want to be... Because you can say if you really have only one program to run for one hour, there's no point in the cluster.  Like when the simulation is going on and just waiting there, fiddling my thumbs and waiting for the results to appear. I want it to be like, it's gone. It's running somewhere else. I can do other stuff in the meantime. I can read literature. I can improve some other stuff. And then once I come back by magic almost, the results are there to be like right for the picking. Yeah. So that is the real power of the cluster system. Yeah. So what should we do now? Yeah, so at this point, I think we should like we are getting close to the four o'clock. We can now well demonstrate what we will be starting in the next, at the start of the next day. Like what we just talked about, that is like basically the next step. Like that is that that change of frame of perspective from I'm running this stuff on my laptop. What am I running it in the cluster with the s run command? That is basically now you're running the same thing there, but you're not getting any benefit, right? Like you're running the same stuff in a command line somewhere else and you're not seeing any benefit.  And this is where we get to the non-interactive working flow and this is what basically everybody uses in cluster environments. Yeah. Should we do some more of these interactive exercises down at the bottom or should we go on? We might want to do, like there was, yeah, let's do a few of these like before we run the series of examples. So there was good questions that like what happens if the job runs out of memory or if it runs out of time? And there are these examples here. Like if you have downloaded, like if you haven't yet cloned this HBC examples repository, you can do it now into your work directory or your home directory. It doesn't really matter. You can try the work directory because that's where you will be running in the future. So that's a better place to store it. But if you cloned the repository in there, there's this memory hoc script that basically just allocates bigger and bigger amounts of memory. And try running it. Let's do it interactively. Yeah. Okay. So I'm removing my existing examples. You don't need to do these. Yeah. I hope there was nothing important in there. And now I run git clone to get it. Okay. And now I am in HPC examples. Yeah. If you run this memory hoc script. So what happens if I run it now? Yeah. If you run it now, it runs on the login node. So basically you will use the resources on the login node. So try running it. Yeah. Does it say at the top, does it say where it's running? Probably not. No. Okay. Yeah. Okay. But yeah. So you can see that it tries to allocate. And there's no limit on the login node. So many users sometimes field the node with the chops. And we have to kill them because we haven't put memory limit on the login node. But you're not supposed to run heavy memory usage chops there. But let's say we want to run it in the queue. So the exercise B. Okay. So we'll use S run 500 megabytes of memory. Python slur memory hoc and 50 megabytes. Yeah. So we're waiting. Okay. So it worked. Yeah. So you. Yep. Yep. So that's as simple as that. Can you run slurm history now? So this is, there's another command for other sites. I think it's the last one over there. So we'll talk about monitoring it later on. But you can well allocate it didn't to register the memory usage yet. But let's try running the C step. Oh, C. So increase the amount of memory. So let's put something that is bigger than the 500 megabytes. Like five gigabytes. Yeah, something like that. Okay. The idea here is to demonstrate what will happen if you run out of memory in the job. And this slurm history command will go into more detail next week. Yes. Okay. I've got resources. Or tomorrow. Oh yeah, tomorrow. Yeah. Yeah. So you can see that we got out of memory error here. So we are. Yeah. And interestingly didn't even print any output, which I'm. I'm pretty sure that's because like if you run the Python without unbuffered output, it might work. So Python dash U, I think it's because of that. Okay. Well, hold it. Let's go then. I'll add that. Okay. But yeah, you can see that like if it runs out of memory. Okay. Now we get some. There we go. Yeah. So about two gigabytes. The job was killed. So there's a bit of leeway in the in the memory that you are allowed to use unless some other task needs that memory in which case your job is killed automatically. Yeah. So this, this is what happens when. So maybe I think we should show the S interactive or. So I see a comment in HackMD about in Helsinki using the interactive command. So when you start these things like S run. Well, how about I demonstrate this other command we have S interactive. So this is probably similar to the Helsinki S interactive command. So we run it. We could give the same slurm options for memory and time and stuff like that. The main reason people use this is that they want graphical applications to work. But so once this starts, we get a new shell. So this shell is on the other computer. And my shell tries to start something automatically. So we see a big mess there. Let's ignore that. But now let's say I run the Python thing. Well, if I run anything here. So it runs and then it stops. But notice I'm still on the node I requested. So I have to exit this shell myself. So there's two ways of doing these interactive things. One is by requesting a session. And then you can do multiple things. And then you have to remember to close the session yourself. Or else it'll keep allocating the resources and well, eventually time out and. That's not good. The other option is what we did with the S run like this where the command is directly on the S run line. And here we wrap the command in S run. So S run allocates resources runs exactly one command and then exits right away. And this is a very important fundamental distinction. And also I guess we see it later on too. When we do the asynchronous serial jobs, you give it a command that runs it and then it frees the resources immediately. Let's see. That shell got crazy. Okay, let's see. Maybe we can what should we do now? Yeah, like I want to clarify a few things in the HackMD that are very good questions. So like these questions relate to like why are we suddenly using these queues? Like why is it important? And the important thing is that we have a lot of resources and those resources need to be shared among multiple users. So these queue systems are meant for like making certain that everybody gets what they need. Like if we just put like say machines and we say that go out there, people go there, some servers will be completely empty and some servers will be completely full and nothing works there because there's too much used there. So the queue system balances the load so that everybody gets what they need and what they ask for. Well, this system is efficient. So the efficiency is something like 90% in our clusters. So like the system is completely filled and that is important because that's basically like we don't waste servers. We don't waste money. Like everybody gets what they need and we still got like, well, we don't just like put stuff there and it goes to waste and money goes to waste. Like it's important to put stuff, do stuff effectively and in scale, when you're doing stuff in scale, you need to be able to create this queue system so that any people to abide by the queue system so that people get what they need. There's also a good question there. Like if I don't run with S run, the stuff runs much faster on the login node. And why is that? And the reason for there is that like if you just run S run, you are asking for one CPU, you're asking for some memory and some time. And in the login node, if you run stuff there without like you're basically taking stuff from other users and then using the all CPUs probably on the machine or your code is might be using. So that's why it's really important to like set your job so that you the job utilizes the resources it's been given and knows how to utilize it. So when you run the simulation on a node, we'll talk about parallel simulations tomorrow. But when you ask for resources, it might be that the job is running on one CPU or it might be that it starts multiple workers and it tries to all of them are forced into one CPU. So either way it will run slower. So it's important to know what your program is doing and ask for the correct resources for the program. And that way it should run the same speed once you get the correct resources. If you ask for let's say a similar node as the login node. Yes, so any other really important questions here? I see we've detected that the Helsinki cluster is not failing. So don't don't don't mess up there because it might affect other jobs if the memory killer isn't engaging properly. So don't run the memory like to become a memory stuff. Can you try running the CC here? So s run the command but then tell it to sleep for two minutes and it might be that it runs. So it allocates the memory and then okay, so it used to be in Triton. There was a process that ran every 60 seconds and checked is a job using too much memory and then killed it. So when this happened you can go over your memory limit until the next 60 second interval happened and then you would get killed. So that couldn't be what the problem is here. And that's why the sleep option was added. So it won't end until it has time to do this. So interestingly also when you run the slurm history command which I showed before. You see let's see we'll go over this more tomorrow but this one M here is what the actual memory usage was. So you notice it says one megabyte this is just wrong and that's because still this only measures it every 60 seconds and not every not instantly even though Triton kills it instantly. So it can be a bit tricky to keep these together. The memory key only engage when they're gone on a set period and then they set intervals and if the memory is running out then they will kill the jobs that are going above the limits. And interestingly this is the kind of thing we talk about in our Triton admin meetings all the time. So there's some really small things that seems like an obvious thing to do but then either it doesn't quite work or there's some other trade off and well yeah. But yeah so just to like let's for tomorrow like what you should gather from this interactive thing is like now we got a first glimpse of the queue system. And this is like the queue system is really what powers the cluster. So everything we said before is like needed for the cluster to work. You need storage you need login notes you need stuff. Like basically you're currently seeing like the veil being opened like you're at the theater. The veil is being opened but the show is about to start and show starts tomorrow when we go into non interactive users because this is like like you're still opening a terminal somewhere. You're running commands interactively and that is not the point the main point of the cluster. The main point of the cluster is that you tell somebody else to do stuff for you and that somebody else is the queue manager.  You run stuff non interactively and you only use the command line and the data copying stuff like that to like then like give the instructions and read the output from there. So these interactive this is just the first glimpse of the queue manager. So you you can run stuff interactively you can give it some limits like memory limit time limit we'll talk about other limits tomorrow. But basically the idea here is that tomorrow we'll have a full day of running non interactive jobs and that is the like 99% of our jobs are run that way.  Then they're basically CEOs of like jobs instead of like they're managing the jobs. They're managing the workers. They are not doing the work themselves. So so basically that is the non interactive idea that we'll be focusing tomorrow. Yeah. And this is why the shell scripting is so important. And we started with that because if you can't make your things run automatically you can't use 6000 processors at once or no for the new CSC Lumi computers tens of thousands or hundreds of thousands of processors at once.


Hello and welcome to the session I am Shashi and I am going to help you with the following question. Question says the angles of elevation of the top of a tower from two points at the distance of four meters and nine meters from the base of the tower and in the same straight line with it are complementary. Prove that the height of the tower is six meters. Let us now start the solution first of all we will draw a simple diagram to represent that problem. Now here AB is the tower now two points C and D are nine meters and four meters away from point B that is the base of the tower and angle of elevation of point A from point D is theta and angle of elevation of point A from point C is 90 minus theta we are given that these two angles are complementary angles we know complementary angles are those angles who have the sum 90 degrees so if one of the angles is theta then other angle is equal to 90 minus theta so we can write let AB is the tower and point C and D are at a distance of nine meters and four meters from point B that is the base of the tower now we are given that point C and point D are in the straight line and angle of elevation of A from these two points are complementary so we can write let angle AB is equal to theta that is angle of elevation of point A from point T this is equal to theta this implies angle ACB is equal to 90 minus theta since these two angles are complementary so angle ACB is equal to 90 minus theta now we have to prove that height of the tower is six meters that is we have to show that AB is equal to six meters now first of all let us consider right triangle ADB in right triangle ADB tan theta is equal to AB upon BD you know tan theta is equal to perpendicular upon base here AB is the perpendicular and BD is the base now we know BD is equal to four meters we are given that distance of point T from base of the tower that is point B is four meters so substituting BD is equal to four meters in this expression we get tan theta is equal to AB upon four let us name this expression as one now we will consider triangle ACB in right triangle ACB tan 90 minus theta is equal to AB upon BC we know tan theta is equal to perpendicular upon base in this triangle this is theta and this is perpendicular this is base so we get tan 90 minus theta is equal to AB upon BC now we know distance of point C from base of the tower that is point B is equal to nine meters or we can simply say BC is equal to nine meters now substituting value of BC in this expression we get tan 90 minus theta is equal to AB upon nine now we know tan 90 minus theta is equal to cot theta so this implies cot theta is equal to AB upon nine now let us name this expression as two now multiplying expressions one and two we get tan theta multiplied by cot theta is equal to AB upon four multiplied by AB upon nine now we know tan theta multiplied by one upon tan theta we know cot theta is reciprocal of tan theta is equal to AB square upon 36 now tan theta and tan theta will cancel each other and we get one is equal to AB square upon 36 now multiplying both the sides by 36 we get 36 is equal to AB square now taking square root on both the sides we get 6 is equal to AB we know square root of 36 is equal to plus minus 6 but height of the tower cannot be negative so we will neglect the negative value that is minus 6 and we get 6 is equal to AB or we can simply write it as AB is equal to 6 meters now we know AB is the height of the tower so height of the tower is equal to 6 meters hence proved this completes the session hope you understood the solution take care and have a nice day


This is Dr. Don, and we're going to take a couple of minutes and walk through a paired sample's T-test using statcrunch. Here's the situation. We have a medical researcher that has a new drug and the researcher wants to determine whether or not a drug, the drug, changes body temperature. So they select seven participants randomly chosen and their temperatures are taken before they take the drug and then 20 minutes after they took the drug the temperatures are taken again. Now we're told to assume body temperatures are normally distributed, which they generally are. And we want to use an alpha of point zero five. Our significance level there is point zero five five percent. And we want to know is there enough evidence to conclude the drug changes body temperature? So let's jump into it. I'll show you how to do it with statcrunch. Here's the data on the seven participants. First column is labeled before and it's got their temperatures and degrees Fahrenheit. And then we've got a column label aphrodur. 20 minutes and those are their temperatures. So to do a two sample T-test paired we're going to go to stat first go down to T stats and we want a paired sample not a normal two sample. And we click on that. First thing we need to do is to select the data in column one which is our before data at sample one. Sample two is in the after column. We don't have to worry about grouping or having any special coding here. We do want to save the differences between the two data sets. So that's important. Check that. We're doing the hypothesis test for the mean difference mu d mu one minus mu two. Our assumed null difference is zero. Our alternative is not equal. The researcher wants to know believes that the drug will make a difference in the before and after temperature. We want to get the critical value. So I'm going to click that and double check make sure that the significance level is what we want point zero five down here at the bottom. I want to select the p-value plot just so we can see that plot which can be interesting. And then we click compute and we got our results. First thing I like to do is just read over this top part to make sure it's what I wanted. I wanted the mean difference with mean two subtracted from mean one and our assumption is of not equal for the claim. The difference for after the mean difference is point five five seven and that's one of the answers that you usually have to get. The other thing we need to get is the standard deviation of the differences. This gives us the standard error. And of course we could back that out, but I'll show you another way to get it. Degrees of freedom is in minus seven. We've got our sample sizes seven minus that is six. Our test statistic is one point five nine six. We've got a critical t-value because I checked that and set the significance level is two point four four seven and there's two of them. There's a plus and a minus because it's two tail and we've got a p-value of point one six one six which is much larger than our significance level. If we go here to our p-value plot we can see that these lines are our test statistic above and below because we want to check to make sure it's as extreme or even more extreme and that can be above the mean a positive difference or a negative difference. The area under the curve here is point zero eight above and point zero eight approximately below and that gives us our total of point one six. So that's the first part. Now let's get that standard deviation of the differences. That's why we got this difference column. I'm just going to go over here to stat again and go to summary stats columns and we want the differences and we want to get the mean click on that hold down the control key get standard deviation and then click compute and there's our mean differences the standard deviation of the differences as well. Again you can see the mean here is the same as the mean there and if you did the arithmetic divide this standard deviation of point nine two three five by the square root of seven you'll get that value right there. So I hope this helps.