55) A horizontal force 10 N is necessary to just hold a block stationary against a wall. The coefficient of friction between the block and the wall is 0.2, the weight of the block is.
(1) 20 N
(2) 50 N
(3) 100 N
(4) 2 N

56) In the figure shown , the coefficient of static friction between the block A of mass 20 kg and horizontal table is 0.2. What should be the minimum mass of hanging block just beyond which block stars moving?
(1) 2 kg
(2) 3 kg
(3) 4 kg
(4) 5 kg