A block of mass m is placed on a smooth wedge of inclination `theta`. The whole system is accelerated horizontally, so that the block does not slip on the wedge. The force exerted by the wedge on the block (g is acceleration due to gravity) will be

Options

A. `mg cos theta`
B. `mg sin theta`
C. mg
D. mg/cos `theta`

Answer

D

Explanation

m g sin `theta = ma cos theta`
`rArr a = (g sin theta)/( cos theta)`
Force exerted by the wedge on block – R = mg cos `theta` + ma sin `theta` = mg cos `theta + m xx (g sin theta)/( cos theta) . Sin theta `
`R = (mg)/( cos theta)`