A block of mass rests on another block of mass

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

A block

A

of mass

2\,\text{kg}

rests on another block

B

of mass

8\,\text{kg}

, which rests on a horizontal floor. The coefficient of friction between

A

and

B

0.2

, while that between

B

and the floor is

0.5

. When a horizontal force

F

25\,\text{N}

is applied to block

B

, the force of friction between

A

and

B

is (1)

3\,\text{N}

(2)

4\,\text{N}

(3)

2\,\text{N}

(4) Zero