Answer the following

State Newton’s second law of motion, in terms of momentum.

According to Newton’s Second law:

Whenever a force is applied on an object there will be change in the momentum of the object.

OR

The rate of change of momentum is directly proportional to the force applied.

From these two statements we should conclude that the change in momentum is only possible by applying a force or a force applied always change the momentum of the object. As we know that the momentum is {} where v is velocity. Now, we know that the mass of the object is constant and if there is change in momentum that will be causing change in velocity. And change in velocity is called acceleration. Hence, if and only if an unbalanced force is applied on any object it will result in change of its momentum which will further results in changing its velocity. So to cause acceleration we must apply an unbalanced force.