Question

Derive the unit of force using the second law of motion.

Answer 1

1. Newton's second law describes the net external force acting on an object is creating an acceleration for the object.
2. For a constant mass, as per Newton's second law, $F=ma$( where $m$ is the mass of the object and $a$ is the acceleration of the object).
3. SI Unit of mass $m$ is $kg$ and SI unit of acceleration is $m{s}^{-2}$.
4. Hence unit of force according to Newton's second law is $kgm{s}^{-2}$.
5. Newton is the SI unit of force.
6. $1kgm{s}^{-2}=1N$.