A block of mass m is in contact with the cart C as shown in the figure

The coefficient of static friction between the block and the cart is `mu`. The acceleration `alpha` of the cart that will prevent the block from falling satisfies.

Options

A. `alpha lt (g)/(mu)`
B. `a gt (mg)/(mu)`
C. `a gt (g)/(mu m)`
D. `a ge (g)/(mu)`

Answer

D

Explanation

N = m `alpha , f le mu N`
`implies mg le mu m alpha`
`implies alpha ge (g)/(mu)`