Question

An object is moving to the right in a straight line. The net force acting on the object is also directed to the right, but the magnitude of the force is decreasing with time. The object will
A) continue to move to the right, with its speed increasing with time.
B) continue to move to the right, with its speed decreasing with time.
C) continue to move to the right with a constant speed.
D) stop and then begin moving to the left.

Answer 1

Answer:

A) continue to move to the right, with its speed increasing with time.

Explanation:

As long as force is positive , even when it is decreasing , it will create positive increase in velocity . Hence the body will keep moving with increasing velocity towards the right . The moment the force becomes zero on continuously decreasing , the increase in velocity stops and the body will be moving with the last velocity uniformly towards right . When the force acting on it becomes negative , even then the body will keep on going to the right till negative force makes its velocity zero . D uring this period , the body will keep moving towards right with decreasing velocity .

Hence in the present case A , is the right choice.