It was calculated that a shell fired from a gun with a certain velocity and at an angle of elevation 5pi/36 rad should strike a given terget.In actual practice,it was found that a hill just prevented the trajectory.At what angle of elevation should the gun be fired to hit the target?-

1. 5pi/36
2. 11pi/36
3. 7pi/36
4. 13pi/36

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.

11

21

31

41