Question

A ball is rolled uphill a distance of 4 meters before it slows, stops, and begins to roll back. The ball rolls downhill 28 meters before coming to rest against a tree. What is the magnitude of the ball’s displacement?

Answer 1

The main assumption is that the ball followed the same way uphill and back, so it was at the same initial point when it rolled back 4 m.

At this moment the displacement was zero (remember that the displacement is the difference between the final position and the initial position).

From that point the ball displaced other 24 m down (28m - 4m = 24 m). And, that is the magnitude of the ball's displacement.

Answer: 24 m.