the ratio of magnitude of work done in moving slowly a block of mass m on a rough inclined surface of inclination 45 degree from bottom to top and from top to bottom is 5. the coefficient of friction between the block and surface is

(a)1/2

(b)2/3

(c)2/5

(d)4/5

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