Question

could u tell me what is limitation of newton's 2nd law ?

Answer 1

Movement should not be too fast

Answer 2

the speed if near the light. the m will be change

Answer 3

But F=dp/dt will still be valid although mass will vary with velocity

Answer 4

we have taken several things for granted...first one is that mass of an object is constant.this is not real.the second one is when two objects are put together their masses add.Both are Newtonian approximations.Newton while deducting the law didnt consider how mass is changing with velocity.suppose mass changed inversely as the velocity then in no case momentum will change.So the law means nothing unless you know how mass changed with velocity