Question

A block of mass 2kg rests on a plane inclined at an angle of 30^o with the horizontal. The coefficient of friction between the block and the surface is 0.7. The frictional force acting on the block is

• A. 10 N
• B. 11.9 N
• C. 12.5 N
• D. 11 N

Answer 1

The correct option is A

10 N

Since the frictional force is self adjusting, the weight component acting down the inclined plane is mgsin?, which comes out to be 2 x 10 sin 30 = 10 N. So the frictional force balancing this downward force will also be 10 N acting up the plane.