what is force class 9

Force is a physical quantity that can cause a change in the state of rest or motion of an object, or a change in the direction, shape, or size of an object. It is an external agent that has both magnitude and direction, and it is measured in Newtons (N), which is the SI unit of force. The formula for force is F = ma, where F is force, m is mass, and a is acceleration. Forces can be balanced or unbalanced, and they can cause three things to happen to a body: change its speed, change its direction of motion, or change its shape. Examples of forces in our daily lives include weight force, the force exerted by a bat on a ball, and the power of a hairbrush on hair during brushing.