A block is kept on a frictionless inclined surface with angle of inclination `alpha`. The incline is given an acceleration 'a' to keep the block stationary. Then a is equal to

Options

A. `g tan alpha`
B. `g`
C. `g cosec alpha`
D. `g//tan alpha`

Answer

a

Explanation

The block will remain stationary when as show
`ma cos alpha = mg sin alpha`
`a = (g sin alpha)/(cos alpha) = g tan alpha`
.