Question

State the principle of moments. Give one device as an application of it.

Answer 1

Hint: The principle of moments can be defined as the state of equilibrium in which the total sum of anticlockwise moment is always equal to the total sum of the clockwise moment. Here, we will understand it in more detail by using the example.

Complete answer:
In other simple words, the principle of moments can be expressed as the body which is in equilibrium where the algebraic sum of the moments of all the forces which acts on the body about the axis of the rotation is zero.
Mathematically, the moment can be defined as the product of force with the perpendicular distance from the pivot (d).
Expressed as: $ M = Fd $
Examples: Principle of Moments is used in our day to day life, such as –
-Sea-saw
-Pendulum
-Turning Foke.

Additional Information:
The moment of inertia of a uniform circular disc about an axis passing through its centre and perpendicular to it can be given by - $ I = M{R^2} $ where “I” is the moment of inertia, M is the mass and R is the distance from the axis of the motion.

Note:
Generally, the principle of moments is used in the lever system where the heavy loads are to be lifted. Hence, by using the principle of moments heavy load can be lifted or replaced by the lower amount of efforts. Don’t be confused between the moments and moments of inertia.