In physics, a force is any interaction that, when unopposed, will change the motion of an object. A force can cause an object with mass to change its velocity, i.e., to accelerate. Force can also be described intuitively as a push or a pull. A force has both magnitude and direction, making it a vector quantity. Force applied on a body is defined as the rate of change in its linear momentum. A rigid body, when acted upon by force, can have two kinds of motion, i.e., linear or translational motion and rotational motion. The turning effect on the body about an axis is due to moment of force (or torque) applied on the body.
The moment of force is equal to the product of the magnitude of the force and perpendicular distance of the line of action of a force from the axis of rotation. A few concepts discussed in this chapter are translational and rotational motions, moment (turning effect) of a force or torque, couple, equilibrium of bodies, the principle of moments, the centre of gravity, uniform circular motion, centripetal and centrifugal force.
Force gives the students a clear understanding about the concepts translational and rotational motions, the moment of a force or torque, couple, equilibrium bodies, the principle of moments, the centre of gravity, uniform circular motion, centripetal and centrifugal force.