Question

how newton's second law of motion is different from first law

Answer 1

Newton's First Law Gives the definition of Force as what actually a Force is....Whereas Newton's Second Law Gives the measurement or We can Calculate the Force By Newton 2nd Law...

Newtons first Law is Also called law of inertia...According to Newtons first law...A body at rest will remain at rest , a body in motion , will keep moving in same direction unless an external Force act on a body...

According to this Law...a body at rest will remain at rest...due to inertia of rest untill and unless " SOMETHING" act on it...

Simillarly if a body is already in motion and moving in one particular Direction then it keep moving in the same direction due to inertia of motion...in oreder to decrease or decrease the speed then again body needs " SOMETHING "...

Here SOMETHING is a force....So Newton first law actually define what actually a force is...

Acoording to Newtons Second law...Force is directly Proportional to the rate of change of momentum...

F = ( mv - mu ) / t = m × ( v-u ) / t = m x a

F = m × a where
m = mass of an object
a = acceleration

F = m x a gives the measurement of Force...