Question

Which of the following statement is correct, when a man walks on a rough surface:

• A. The frictional force exerted by the surface keeps him moving
• B. The force which the man exerts on the floor keeps him moving
• C. The reaction of the force which the man exerts on floor keeps him moving
• D. None of the above

Answer 1

The correct option is C The reaction of the force which the man exerts on floor keeps him moving

When the man pushes the rough surface backward on walking, then surface (from Newton's third Law) applies reaction force in forward direction. It occurs because there is friction between man & surface.