Compare the motion of two gray whales. Which gray whale was moving at a higher speed?
a gray whale that moved 35kilometers in 5hours a gray whale that moved 40kilometers in 5hours
An object's speed tells you how fast the object is moving. Speed depends on both distance and time.
Distance tells you how far the object has moved. One unit used to measure distance is the kilometer.
Time tells you how long the object has spent moving. One unit used to measure time is the hour.
Think about two objects moving for the same amount of time. The object that is moving faster will go a farther distance in that time. It is moving at a higher speed.
Look at the distance each gray whale moved and the time it took to move that distance.
One gray whale moved 40 kilometers in 5 hours.
The other gray whale moved 35 kilometers in 5 hours.
Notice that each gray whale spent the same amount of time moving. The gray whale that moved 40 kilometers moved a farther distance in that time. So, that gray whale must have moved at a higher speed.