Question

A body is moving with uniform velocity , find the resultant force on the body.

Answer 1

Assume an event a car is moving. So first it was at rest then it slowly accelerates then remains at a constant velocity. Now select a sub event that is the point of time when the car moves in a constant velocity. Constant velocity means acceleration must be zero.(since acceleration is the rate of change of velocity when change in velocity is zero acceleration is zero). We know that for any external force to act we need acceleration. And here acceleration is zero as such applied force is zero.

**Here we can say about only external force while internal force may not be compulsorily zero**

Hope it helped still if you have any doubts can ask in comment section.

Answer 2

B'cuz the body is moving with uniform velocity.........there will 0 acceleration.....
And therefore..... resultant force F=ma
F=m×0
F=0