Question

deduce first law of motion from second law of motion

Answer 1

Newton's first law of motion is important so that you can understand the next two. It states that if an object is not moving, than the net force acting upon it is 0; which is the same amount of force on an object moving at a constant velocity.

Answer 2

$\textbf{ Hello Mate! }$

By second law of motion we know that

$\textbf{ F = ma }$

Now, if no force is applied then F = 0

0 = ma

Now, mass can't be 0 hence

0 = a

First equation of motion we get

v - u = at

v - u = (0)(t)

$\textbf{ v = u }$

Hence, final velocity = initial velocity.

Means object in motion will remain in motion and at rest will remain at rest until and unless external force is applied.

Have great future ahead!