Hi,

The conclusion is that a change in velocity can only occur if a force is present. But this is just what Newton's first law states. In other words, it appears that the first law can be derived from the second, and if it is nothing more than a consequence of the second, then the first law is redundant.

Newton's first law of motion predicts the behavior of objects for which all existing forces are balanced. ... The second law states that the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object.

Hope this helps

Wish you luck

hi...

So,Newton's 2nd Law of motion states that, force F acting is equals to the rate of change in momentum δPδt

So, if a particle of mass m was initially moving with velocity u changed its velocity to v in time t ,its change in momentum ( δP )= m(v−u)

So, δPδt=m(v−u)t−0=m(v−u)t

So, F=m(v−u)t

Now, if F=0 ,

m(v−u)t=0

so, v−u=0

so, v=u

and if u=0,v=0

That means,when no force is acting, a body that was initially at rest i.e u=0 ,will remain at rest,so v=0

Or,if it was moving with constant velocity u ,it will be moving with the same velocity i.e v=u (means, final velocity ( v ) = initial velocity( u )

This is the Newton's 1 st Law of motion.