When a man walks towards the east, the frictional force is applied opposite to the direction of his motion.

Here's why:

* Friction and Motion: Frictional forces always oppose the relative motion between two surfaces.

* Walking and Friction: When a man walks, his feet push backward against the ground. This backward push creates a forward frictional force from the ground on his feet. This forward frictional force is what propels him forward.

Therefore, the frictional force acts in the westward direction, opposing the eastward motion of the man.