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.
If both the blocks are stationary, the force exerted by ground of block A is

Options

A. `(3a)/(4)`, upwards
B. `(4a)/(3)` upwards
C. `(3a)/(5)` upwards
D. `(4a)/(5)` upwards

Answer

A

Explanation

To keep regular contact
`a sin theta = b cos theta`
`b = a tan theta = (3)/(4) a`