A uniform cube of side a and mass m rests on a rough horizontal table. A horizontal force F is applied normal to one of the faces at a point that is directly above the centre of the face, at a height 3a/4 above the base. The minimum value of F which the cube begins to tip about the edge is ....(Assume that the cube does not slide).

Options

A. `(2 mg)/(3)`
B. `(mg)/(4)`
C. `(3 mg)/(4)`
D. `mg`

Answer

A

Explanation

(a) To tilt about `A`, torque of `F` about `A` should be greater than torque of `mg` about `A`.
`F (3a)/(4) ge m g ((a)/(2)) rArr F ge (2 mg)/(3)`.