Answer
a. Speed of the ball at the end, fastest to slowest: B, A=C
b. Time for the ball to reach the end, longest to shortest: A, B, C
c. Average speed of the ball, greatest to least: C, B, A
Note that the tracks are stated to be of equal length, but the textbook art does not represent them that way.
Work Step by Step
a. The ball is moving fastest at the end of track B because it has dropped the farthest from its starting point.
The ball is moving equally fast at the ends of tracks A and C because the ball has dropped an equal distance from the starting point.
b. On track A the ball moves at medium speed almost the entire time. On track B the ball mostly moves at the same medium speed, but also spends some time moving more quickly. On track C, the ball spends even more time moving quickly.
Since the problem specifies that all three tracks are the same length, track A takes the longest time to complete and track C takes the shortest time.
c. See previous explanation. Average speed is distance divided by time, and the distances are equal.
Track C takes the shortest time and so the ball has the greatest average speed. The ball on track A takes the longest time and it has the smallest average speed.
