Question

The frictional force direction is _________ to the direction of the body tends to move relative to the other
A) Is always opposite
B) Is always towards
C) Sometimes opposite
D) Sometimes towards

Answer 1

Hint Friction force opposes the motion of a body in general. The friction force, air drag force, and viscosity are some of the day to day examples of friction force.

Complete step by step answer
Friction forces are very evident and are experienced in day to day life. When we are walking, our feet experience friction force with the ground, which is why we can keep our feet stable on the ground. When we want to push a box on the ground, it is a friction force that makes it difficult to push it easily.
The friction force depends on the kind of surface. Some surfaces like glass are smoother than other surfaces like rocky surfaces. However, the friction force only acts when an external force is applied to the object.
This can be understood as follows: on a box on the ground, if we apply an external force, then the frictional force will act and oppose the external force. When the external force is removed, no friction force exerts on the object and hence it doesn’t move.
So we can say that friction force is always opposite to the direction of the movement of the body.
So option (A) is correct.

Note
While the formula of friction force does not indicate a direction for force, we should intuitively know that it will only oppose external force. The friction force on any object depends on its weight and coefficient of friction of the surface.