Question

A ball hits a vertical wall horizontally at 10m/s bounces back at 10 m/s:
a) There is no acceleration because 10 10 0
b) There may be an acceleration because its initial direction is horizontal
c) There is an acceleration because there is a momentum change
d) Even though there is no change in momentum there is a change in direction. Hence it has an acceleration​

Answer 1

Answer:

(d)

Explanation:

It is important to remember that velocity is a vector, hence not only the magnitude, but also the direction matters while calculating changes in it.

While the magnitude of the velocity has remained the same through the process, the direction has changed by 180°, and, according to Newton's First law of motion, there cannot be a change in momentum without the application of a force, i.e., there cannot be a change in velocity without the application of acceleration.

Hence, the option (d) is the most appropriate out of all of these.