Three blocks A, B and C are kept as shown in the figure. The coefficient of friction between A and B is 0.2, B and C is 0.1, C and between C and ground is 0.0. The masses of A, B and C are 3 kg, 2kg and 1 kg respectively, A is given a horizontal velocity 2 m/s. A, B and C always remain in contact. Find (in J) the magnitude of total work done by friction.

$K_f-K_i=W_{friction}$ (K= Kinetic energy)

Q. In the figure shown, the coefficient of static friction between $C$ and ground is $0.5$, coefficient of static friction between $A$ and $B$ is $0.25$, coefficient of static friction between $B$ and $C$ is zero. The minimum value of force $F$ (in Newton), to cause sliding between $A$ and $B$ is (Masses of $A,B$ and $C$ are respectively $2kg,4kg$ and $5kg$).

Q. Masses of block A, B and C are 10 kg, 2kg and 3kg respectively and they are arranged as shown in the figure. There is a uniform electric field towards right of magnitude 10 N/C and block C has charge 0.5 C. If frictional coefficient between block A and the floor is 0.1, between block C and wall is 0.2 and there is no friction between A and B, then which of the following option(s) is/are correct: (Assuming pulley and string to be ideal)

Q. Three blocks $A,B$ and $C$ of masses $1kg,2kg$ and $3kg$ respectively are arranged as shown in the figure. The coefficient of friction between different surfaces are shown in figure. A force of magnitude $20N$ acts on block $B$ in horizontal direction, find the acceleration of block $C$

Q. Find the least horizontal force P to start motion of any part of the system of the three blocks resting upon one another as shown in Fig. The weights of blocks are A=300 N, B = 100N, and C =200 N. Between A and B, the coefficient of friction is 0.3, between B and C is 0.2, and between C and the ground is 0.1.