Ball A is dropped from rest from a window . At same instant ball B is thrown downwards and ball C is thrown upwards from the same window .which statement concerning the ball is necessarily true if air resistanse is neglected ? and why?

[A] All 3 balls strike the ground at same time.
[B] All 3 balls strike the ground at same velocity;
[C] All 3 balls have same velocity at any instant.
[D] all 3 bqlls have same accln at any instant.

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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