A high-school science student claims to have invented simple glass marbles that collide with perfectly elastic collisions. He demonstrates this by shooting one marble at another; you hear the snap of the collision and then see the marbles move apart. Repeated measurements always indicate that the collision is elastic within the measurement accuracy of the equipment. Is the collision elastic? Why or why not?

Three identical balls are placed on a frictionless horizontal surface touching each other. They stick to each other because of adhesive. Another ball of same radius and mass m is placed over the void created by the three balls. Find the forces applied by the balls kept on the floor to each other if the system remains in equilibrium.

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.

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