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Question
State and explain Newton’s second law of motion.
Solution
Newton’s Second law of motion states that the force ‘F’ acting on a body of mass ‘m’ producing acceleration ‘a’ is equal to the product of the mass and acceleration of the body. That is, F = ma
It can be derived from the concept of momentum.
Suppose a body of mass ‘m’ has initial velocity ‘u’ and after time ‘t’ its velocity becomes ‘v’. The initial momentum is, Pi = mu
The final momentum is Pf = mv
The change in momentum with respect to time ‘t’ is
= (mv − mu)/t = m (v − u)/t = F …….(1)
We know, acceleration, a = (v − u)/t
So, (1) implies,
F = m(v − u)/t = ma
Which is Newton’s Second law of motion.
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