A block of mass m is placed on a smooth horizontal floor is attached to one end of spring.The other end of the spring is attached to fixed support.When spring is vertical it is relaxed. Now the block is pulled towards right by a force F , which is being increased gradually. When the spring makes angle 53° with the vertical,block leaves the floor. Then find the force constant of the spring.

Answer is ...5mg/2l

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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