A block A of mass 100 kg rests on another block B of mass 200 kg and is tied to a wall as shown in the figure. The coefficient of friction between A and B is 0.2 and that between B and ground is 0.3. The minimum force required to move the block B is `(g=10ms^(-2))`

Options

A. 900 N
B. 200 N
C. 1100 N
D. 700 N

Answer

c

Explanation

Friction force between A andB and between blockB and surface S will oppose F
`thereforeF=F_(AB)+F_(BS)=mu""_(AB)M_(A)g+mu_(BS)(m_(A)+m_(B))g`
`=0.2xx100xx10+0.3(100+200)xx10`
`=200+900=1100N`