A block of mass 5 Kg is suspended from the end of a vertical spring which is stretched by 10cm under the load of the block. the block is given a sharp impulse from below so that it acquires an upward speed of 2m/s . How high will it rise?.........i

actually i saw the following equation in the solution

1/2kx² + 1/2mv² = ½(h – x)² + mgh

i didn't understand how (h-x) can be written....................PLZ EXPLAIN

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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