Question

The S.I. unit of weight is :
A. Kilogram
B. Gram
C. Newton
D. Milligram

Answer 1

Hint:- Let us write the formula weight because after expanding that we can easily calculate the unit of weight.

Complete answer:
As we know that weight of a body is its relative mass or the quantity of matter contained by it, giving rise to a downward force; the heaviness of a person or thing or in other word we can say that the weight of an object is the force acting on the object due to gravity.
And weight is denoted as W.
As we know that formula of weight that W = mg
Where m is the mass of the body. So, its unit will be kilogram (kg).
And g is the gravity of Earth or we can say that it is the net acceleration that is imparted to objects due to the combined effect of gravitation and the centrifugal force and its unit is $m/{\sec ^2}$
Now weight of the body is = mg = $kg \times \dfrac{m}{{{{\sec }^2}}} = \dfrac{{kg.m}}{{{{\sec }^2}}}$
Now as we know that $kg.m/{\sec ^2}$ is also written as newton(N).
So, the S.I unit of the weight of the body will be Newton(N).

Hence, the correct option will be C.

Note:- Whenever we come up with this type of problem where we are asked to find the unit of any quantity. Then we first write the formula to calculate that quantity and then in place of values we put the unit of every quantity. After solving that we will get the required S.I. unit asked for that quantity (here weight).