A block of mass `m_(1)` rests on a rough horizontal plane with coefficient of friction as `mu`. A light strin attached to this block passes over a light frictionless pulley and carries another block of mass `m_(2)` as shown in figure. If the system is just about to move, then find the value of `mu`.

Options

A. `(m_(2) cos theta)/(m_(1) - m_(2) sin alpha)`
B. `(m_(1) sin alpha)/(m_(1) - m_(2) sin alpha)`
C. `(m_(2) cos alpha)/(m_(1) + mu_(2) sin alpha)`
D. `(m_(1) sin alpha)/(m_(1) + m_(2) sin alpha)`

Answer

A

Explanation

`T = m_(2)g` …(1)
`N + T sin alpha = m_(1)g` ….(2)
`mu N = T cos alpha` ….(3)