Question

A ball with the momentum p strikes a wall and bounce off.The change in the ball's momentum is ideally. a) 0 b) -p c) 3p d) -2p​

Answer 1

Answer:

If initial momentum is p then final momentum will be -p as the direction of motion is reversed.

So, Δp = P(final) - P(initial) = -p - p = -2p

Answer 2

Given,

The momentum of the ball = p

To Find,

The change in momentum of the ball when it strikes the wall and bounces off.

Solution,

In Newtonian mechanics, line force, translation force, or just force is the product of the weight and speed of an object. It is a vector volume, with size and direction. If m is the weight of an object and v is its velocity (and it is the value of the vector), then the force of the object p is p.

p = mv

Since, the ball bounces back so the momentum will be -p due to the change in direction of the velocity.

Change in momentum = Δp = p(final)-p(initial)

Δp = -p-p = -2p

Hence, the correct answer is option (d) -2p.