Inertia Inertia is the resistance of a body to change its state of motion. o o
A body at rest wants to be at rest A body in motion wants to be in motion
Have you experienced jerk when brakes are suddenly applied to the vehicle?
This happens because initially the car was in motion; the body was also in motion. Later, due to the application of brakes, the car came to rest; but the body due to its inertia still wants to be in motion. Therefore, the body doesn’ t come to rest at once and experiences jerk.
Galileo’ s Law of Inertia o
Aristotle’ s Law was falsified by Galileo. Galileo corrected Aristotle’ s law saying“ An external force is required to keep a body in motion, only if resistive forces are present” o
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According to this law, A body moving on a frictionless surface should move with constant velocity.
A body at rest is considered equivalent to a body in uniform motion( In both cases, acceleration = 0; net force = 0)
Galileo’ s law is the basis of Newton’ s 1 st Law of motion