Two boxes of masses m and 3m are stacked. the surface between the more massive box and the horizontal surface is smooth and the surface between the boxes is rough. if the less massive box does not slide on the more massive box, what is the static friction force on the less massive box?

The friction coefficient is .

Explanation:

Given that,

Mass of first box = m

Mass of second box = 3m

Let the static friction force on the less massive box is .

Since the small box is not slide, they have the same acceleration.

We need to calculate the acceleration

Using balance equation

....(I)

....(II)

Adding both the equation

Put the value of a in equation (II)

We need to calculate the friction coefficient

Using formula of frictional force

Hence, The friction coefficient is .

d

explanation:

i think the answer is d. but im not sure!