Question

An object with mass m and speed v directed to the right strikes a wall and rebounds with
speed v directed to the left.
a) What is the change in the object's momentum?
b) What is the change in the object's kinetic energy?

Answer 1

Answer:

Explanation: This is an example of the third law of Newton.

Here as we can see that neither the mass or the magnitude of velocity has been changed. So now,

The change in momentum is ∆P=m∆V, as there is change in the velocity (sign) is 2V hence the change in momentum is 2mV.

The change in kinetic energy is zero, as ∆K.E.=1/2[mV^2-mV^2]=0