Question

Commonly used gadgets or devices are based on principal of Newton law of motion 9 STD

Answer 1

Newton's First Law states that " every object which is at rest or uniform motion continues to be in state of res or uniform motion unless compelled to change its state by action of net force."

Example:A space creft far from any source of gravity would need no thrust to keep it moving at a constant speed in a given direction.Once set in motion, it continues to move forever without propulsion since there is no frcition is space.

Second law of motion " Rate of change of momentum of the body is directly proportional to the force acting on it."

Example:Fielder in a cricket match pulls his hand backwards to reduce impact of impulse force.Working of air bags to prevent the time of injury.

Third law of motion states " For every action there is equal and opposite reaction "

Example:Working Principle of Rocket.Recoil of a gun.

Answer 2

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