A spring of mass m and natural length L is compressed vertically downward against the floor so that its compressed length becomes L/2 . On releasing, the spring attains its natural length, If k is the stiffness constant of the spring, then the work done by the spring on the floor is:-

(a) 0 (b) (1/2) k L ² (C)(1/2) k (l/2) ² (d)k L ²

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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