Method To Find The Direction Of Frictional Force

(i) Explain why friction is necessary to make the disc to roll in the direction indicated. (ii) Give the direction of frictional force at B , and the sense of frictional torque, before perfect rolling begins. (iii) What is the force of friction after perfect rolling begins?

Frictional forces are

A block of mass 2 kg is pressed against a rigid vertical wall by a horizontal force of 100 N. If co-efficient of static and kinetic friction are each equal to 0.3 then find the magnitude and direction of frictional force on the block.

What is the direction of frictional force actiog on a body moving or sliding towards east ?

A body slides down an inclined plane having friction. Indicate the directions of the frictional force and the reaction of the plane on the body.