Which one of the following statements about kinetic friction and the work it performs…
PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials
Problem
Which one of the following statements about kinetic friction and the work it performs on a moving body is correct?
(a) The work done by kinetic friction is proportional to the square of the speed of the body.
(b) Kinetic friction does negative work equal in magnitude to fk multiplied by the displacement along the direction of motion.
(c) Kinetic friction does zero work when a body slides with constant speed because the kinetic energy does not change.
(d) Kinetic friction always does positive work on a moving body.