Question

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

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

Answer 1

The correct option is C 1/4

$\begin{array}{c}\text{Correct option is}\left(c\right)\\ \text{For}c\Rightarrow mg-T=ma---\left(1\right)\\ \text{For}A,B\left(\text{system}\right)\Rightarrow \\ \text{putting in}eq\text{. (1)}\\ g/4=a\end{array}$

$\text{on}\begin{array}{cc}A;f& =ma\\ \mu N& =m\left(g/4\right)\\ \mu mg& =m\left(q/4\right)\\ \mu & =1/4\end{array}$