Question

As shown in figure a block of mass m is attached with a cart. If the coefficient of static friction between the surface of cart and block is μ than what would be acceleration α of cart to prevent the falling of block ? 

(A) α > (mg / μ) 

(B) α > (g / m) 

(C) α ≥ (g / μ) 

(D) α < (g / μ)

Answer 1

Correct option: (C) α ≥ (g / μ)

Explanation:

block will not fall when frictional force ≥ weight of block

μmα ≥ mg

μα ≥ g

α ≥ (g / μ)