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