Question

In the arrangement shown in the figure, there is friction between the blocks of mass m and 2m. Block of mass 2m is kept on a smooth horizontal plane. The mass of the suspended block is m. If block A is stationary with respect to block B. The minimum value of coefficient of friction between m and 2m is:

• A. $\frac { 1 } { 2 }$
• B. $\frac { 1 } { \sqrt { 2 } }$
• C. $\frac { 1 } { 4 }$
• D. $\frac { 1 } { 3 }$

Answer 1

Answer: (C)

$\frac { 1 } { 4 }$

Answer 2

mg = (4m)a

g = 4 × µg ̃ µ = $\frac { 1 } { 4 }$