Question

show that newton first law of motion is a special case of newton second law.

Answer 1

answers was briefly explained in the images

Answer 2

Explain newton's first law of motion?

newton's first law of motion states that an object in motion stays in motion unless acted upon by an outside force.

Newton's second law of motion? 

Newton's 2nd law state that the rate of momentum is proportional to the impressed force & the change in momentum takes place in the direction of force.

Mathematically ,

F = dP/dt = m dv/dt + vdm/dt = m dv/dt = ma [for constant mass system dm/dt = 0]