Three blocks of masses 3kg, 6kg and 1kg are connected by a string passing over two smooth pulleys tached at the two ends of the horizontal surface. If the co-efficient of friction between the block and t surface is 0.6, the frictional force acting on the block of mass 6 kg is

Options

A. 36 N
B. 30 N
C. 20 N
D. 10 N

Answer

C

Explanation

`f_(s(max))=mu Mg=36N," "T_1=10N and T_2=30N`
`"Friction force f"=20N," "20 < f_(s(max)) :.f_s=20N`