Question

In vertical direction, weights are
balanced by frictional forces.
Consider ( mathrm{FBD} ) of block ( mathrm{A} ) and ( mathrm{B} ) as shown
in diagram below.
As the blocks are in equilibrium, balance
forces are in horizontal and vertical
direction. For the system of blocks ( (mathrm{A}+ )
B).
( F=N )
For block ( A, F_{A}=20 mathrm{N} ) and for block ( B )
[
F_{B}=F_{A}+100=120 N
]

# Given in the figure are two blocks A and B of weight 20 N and 100 N, respectively. These are being pressed against a wall by a force F as shown. If the coefficient of friction between the blocks is 0.1 and between block B and the wall is 0.15, the frictional force applied by the wall on block B is: [JEE MAIN 2015] 2 ODN A B 2011

Solution