Always had a doubt. Suppose a block is kept on top of another block which is placed on ground. All surfaces are smooth. If the lower block is moved forward with any accl, then the block above it moves bckward with respect to the lower block. Though it is common sense but what is the real concept related to it. and what will be the accl of the above block.

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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