A cart of mass M has a block of mass m in contact with it as shown in the figure-2.133. The coefficient of friction between the block and the cart is `mu`. What is the minimum acceleration of the cart so that the block m does not fall ?

Options

A. `(g)/(mu)`
B. `(mu)/(g)`
C. `mu g `
D. `(M mu g)/(m)`

Answer

A

Explanation

Let the acceleration of the cart be a , then normal reaction on cart is N = ma and frictional force between block and cart is `f = mu N = mu `ma .
For equilibrium
`mu ma = mg`
`a = (g)/(u)`