Two smooth block are placed at a smooth corner as shown in fig. Both the bloks are having mass m. We apply a force F on the block m. Block A presses block B in the normal direction, due to which pressing force on vertical wall will increase, and pressing force on the horizontal wall decreases, as we increases `F(theta = 37^(@)` with horizontal).

As soon as the pressing force on the horizontal wall by block B become zero, it will lose contact with ground. If the value of F further increases, block B will accelerate in the upward direction and simulaneously block A will towards right.
What is the minimum value of F to lift block B from ground?

Options

A. `(25)/(12) mg`
B. `(5)/(4) mg`
C. `(3)/(4) mg`
D. `(4)/(3) mg`

Answer

C

Explanation

Solving equations acceleration can be calculated
`N cos 37^(@) =mg..(1) N sin 37^(@) =F`
`tan 37^(@) = (F)/(mg) (3)/(4) = (F)/(mg)`
`F = 3/4 mg`
.