Work Done by Friction

A block of 1 kg is kept on a rough surface of an elevator moving up with constant velocity of 5 m/s. In 10 second work done by normal reaction (no sliding on incline surface) (i) from ground frame is 320 J (ii) is equal to work done by friction force in elevator frame (iii) is equal to work done by friction in ground frame

A block of mass m is kept over another block of mass M and the system rests on a horizontal surface. A constant horizontal force F acting on the lower block produces an acceleration (F)/(2(m+M)) in the sytem. The two blocks always move together. Consider displacement d of the system. a. Find the work done by friction on bigger block. b. Find the coefficient of kinetic friction between the bigger block and the horizontal surface. c. Find the frictional acting on the smaller block. d. Find the work done by the force of friction on the smaller block by the bigger block. e. Find the work done by static friction on bigger block.

A plank of mass 10 kg and a block of mass 2 kg are placed on a horizontal plane as shown in the figure. There is no friction between plane and plank. The coefficient of friction between block and plank is 0.5 .A force of 60 N is applied on plank horizontally. In first 2 s the work done by friction on the block is

A person of mass 2 kg is moving with speed 5m/s jumps on the trolley of mass 3 kg which is initially at rest. There is no friction between trolley and ground but there is friction between trolley and person. After some time both achieve common velocity. Find the work done by friction on trolley in Joules.

Consider the system shown in the figure. Coefficient of friction between the block and table is mu=0.5. The system is released from rest. Find the work done by friction, when the speed of block is 10 m/s (m=1kg)

A block of mass m is connected with a rigid wall by light spring of stiffness k . Initially the spring is relaxed. If the block is pushed with a velocity v_0 , it oscillates back and forth and stops. Assuming mu as the coefficient of kinetic friction between block and ground, find the work done by friction till the block stops.

A body of mass 2 kg initially at rest moves under the action of an applied horizontal force of 7N on a table with coefficient of kinetic friction =0.1 . Calculate the (a) work done by applied force in 10s. (b) work done by friction in 10s. (c ) work done by the net force on the body in 10s. (d) change in K.E. of body in 10s, and interpret your result.