Force and Motion

FORCE AND MOTION

According to Aristotle a Greek Philosopher and Scientist, the natural state of earthly bodies is ‘rest’. He stated that a moving body naturally comes to rest without any external influence of the force. Such motions are termed as ‘natural motion’ (Force independent). He also proposed that a force (a push or a pull) is needed to make the bodies to move from their natural state (rest) and behave contrary to their own natural state called as ‘violent motion’ (Force dependent). Further, he said, when two differnt mass bodies are dropped from a height, the heavier body falls faster than the lighter one.

Galileo proposed the following concepts about force, motion and inertia of bodies:

i.                     The natural state of all earthly bodies is either the state of rest or the state of uniform motion.

ii.                     A body in motion will continue to be in the same state of motion as long as no external force is applied.

iii.                     When a force is applied on bodies, they resist any change in their state. This property of bodies is called ‘inertia’.

iv.                     When dropped from a height in vacuum, bodies of different size, shape and mass fall at the same rate and reach the ground at the same time.