The basic principal of physics is defined by parameter like force which gives birth to many other mechanical parameter like stress, momentum, moment etc. Today we study about force and its application.


It is physical quantity that cause a body to move. We experience force in everyday life like playing baseball, soccer etc. It can be understood in simpler way. When a push or pull is applied on a body, the body moves in the direction of force. The push or pull is force here and the movement of ball is effect of force.

For force to be applied on a body, physical contact should must be present between the two bodies, the one which applies force and the other on which force is applied.  Force is defined as product of mass and acceleration.

Force = Mass × Acceleration

Its unit is kg/m^2 or gram/cm^2. This is also called as Newton. Sir Issac Newton derived this physical quantity.


Moment is nothing but the product of Force and force arm. Don't panic, I will make you understand in very simpler way. See the figure below and suppose "F" be the force applied on the body. Consider A as moment centre. The force is applied at distance D from the body. This will tend the body to rotate or move in the direction of force . This turning effect is called moment about A.

The total force here is nothing but the actual force and the length from which force is applied.

Therefore, Moment = Force × Length

Note the force applied is in perpendicular direction. Its unit is Newton-meter. As because force has unit Newton and length is in meter.
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