Acar drives 500 m, turns around and drives 500 m back to its starting point. what total
distance has it traveled? what is the car's total displacement?
an athlete runs 50 min 10 s and another 150 min 40 s. determine her average velocity.
what is the average speed of a cheetah that sprints 100m in 4 s? how about if it sprints 50m in
2 s?
a runner makes one lap around a 400m track in a time of 25.0 s. what was the runner's
average speed? what is the runner's velocity?

Amerry-go-round of radius r, shown in the figure, is rotating at constant angular speed. the friction in its bearings is so small that it can be ignored. a sandbag of mass m is dropped onto the merry-go-round, at a position designated by r. the sandbag does not slip or roll upon contact with the merry-go-round. how would you rank the following different combinations of m and r on the basis of the angular speed of the merry-go-round after the sandbag "sticks" to the merry-go-round from largest to smallest. a) m = 10kg, r = 0.25r b) m = 20kg, r = 0.25r c) m = 10kg, r = 0.50r d) m = 10kg, r = 1.0r e) m = 15kg, r = 0.75r f) m = 40kg, r = 0.25r