Choose the correct option:

A weightlifter lifts a weight off a ground and holds it up:

(a)work is done in lifting as well as holding the weight

(b)no work is done in lifting the weight and holding it

(c)work is done in liftting the weight but no work is done in holding it up

(d)no work is done in lifting the weight but work is done in holding it up.

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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