Question

Having been kicked, a soccer ball rolls past a kid with a stopwatch. At the moment the ball passes the kid, it has an initial velocity of 4.0 m/s and the watch reads 10.0 s. If the watch reads 23.3 s when the ball stops rolling, what is its average acceleration?

Answer 1

The ball rolls to a rest from 4.0 m/s in a span of 23.3 s - 10.0 s = 13.3 s, so the average acceleration is

(0 - 4.0 m/s) / (13.3 s) ≈ -0.30 m/s²