Extra Problems - Introduction

You will find the following numbers useful. The speed of light is 3x105 km-sec-1.

1 AU is 1.5x108 km.

One year = about 3x107 seconds.

1 light year is about 1013 km.

  1. 104x106 = ?
  2. 104/102=?
  3. (1016)1/2 = ?
  4. 6x102x3.5x103 =?
  5. (64x108x36x1012)1/2 = ?
  6. How long does it take light to travel from the Sun to Jupiter? (Jupiter is roughly 5 AU from the Sun).
  7. A radar pulse takes 2 hours to travel from Earth out to an asteroid and return. How far away is the asteroid?
  8. Two galaxies are moving apart at 15,000 km/sec. If they are 6x108 ly apart, how long ago did they begin moving apart (assume they separate at a constant speed). Note: Be sure not to mix light years and km as units here. Convert one to the other, it doesn't matter which.
  9. In the previous problem, you got an answer in seconds. How many years is it?