6.A machine gun fires 10 bullets/s, each of mass 10g, the speed of each bullet is 20 cm/s, then force of recoil is:

7.A block is moving up an inclined plane of inclination 60 degree with velocity of 20 m/s and stops after 2.00 s. If g = 10 m/second square then the approximate value of coefficient of friction is:

8.A block A of mass 2 kg rests on another block B of mass 8 kg which rests on a horizontal floor. The coefficient of friction between A and B is 0.2 while that between B and floor is 0.5. When a horizontal force 25 N is applied on the block B, the force of friction between A and B is:

9.Starting from rest, a body slides down a 45 degree inclined plane in twice the time it takes to slide down the same distance in the absence of friction. The coefficient of friction between the body and the inclined plane is:

10.A block of mass 2 kg is placed on the floor. The coefficient of static friction is 0.4. If a force of 2.8 N is applied on the block parallel to floor, the force of friction between the block and floor is: (Take g = 10 m/second square)