Question

Explain Newton’s second law of motion with the help of an example.

Answer 1

Hint: Laws of motions or Newton’s laws of motion are the fundamental laws which are used in classical mechanics. There are three of them. The first law is also called the law of inertia. The second law explains about the motion of the body while the third law tells us about the forces.

Complete step by step answer:
According to Newton’s second law, the force acting on a body is given by the product of mass of the body and the acceleration produced in the body on account of the external force acting on it.
Mathematically we can write as: \[\overrightarrow{F}=m\overrightarrow{a}\]
Here, we have used the vector sign to denote the force and the acceleration since they are vector quantities while mass is a scalar quantity.
We can also write Newton’s second law in terms of momentum. According to Newton’s second law, the force acting on the body is equal to the rate of change of the momentum of the body.
Mathematically we can write as: \[\overrightarrow{F}=\dfrac{d\overrightarrow{p}}{dx}\]
Considering an example: Riding a bicycle is an example of Newton’s second law of motion. The bicycle is the mass. We use our leg muscles pushing on the pedals of the bicycle is the force. When we push on the pedals, the bicycle accelerates. We are increasing the speed of the bicycle by applying force to the pedals.

Note:
It is not necessary that application of force will always result in acceleration of the body. Suppose we are applying our muscular force to move a very heavy object. The force is acting on the body but the body does not move, hence, the acceleration is zero. The SI unit of Force is Newtons and the SI unit of mass is kg.