Question

State the law of conservation of momentum. Why is a person hit harder when he falls on a hard floor than when he falls on sand from the same height? A bullet of mass 20g is fired horizontally with a velocity 100ms⁻¹ from a pistol of mass 1.5 kg. Calculate the recoil velocity of the pistol.

Attempt either (I) with all sub parts or (II) with all sub parts from the following two questions-

Meenu observed that as a stone of mass 1kg falls freely from a height 1m, its potential energy gets converted into kinetic energy. Therefore, its potential energy decreases and kinetic energy increases. As the stone touches the ground, all its potential energy is converted to the kinetic energy.

Renu observed that as a stone of mass 1kg falls freely from a height 1m, its potential energy gets converted into kinetic energy. Therefore, its potential energy decreases and kinetic energy increases. As the stone touches the ground, all its potential energy is converted to the kinetic energy.

A force of 20 N displaces an object by 5 meters in the direction of the force. Calculate the work done.