Question

A man is standing on a plank which is placed on a smooth horizontal surface. There is sufficient friction between the feet of man and plank. Now man starts running over plank, correct statement is/are

• A. Work done by friction on the man with respect to the ground is negative.
• B. Work done by friction on the man with respect to the ground is positive.
• C. Work done by friction on the plank with respect to the ground is positive.
• D. Work done by friction on the man with respect to the plank is zero.

Answer 1

Answer: (A), (C), (D)

The correct options are
A Work done by friction on the man with respect to the ground is negative.
C Work done by friction on the plank with respect to the ground is positive.
D Work done by friction on the man with respect to the plank is zero.