A 50-Kg Box Slides Up an Inclined Plane at a Constant

Multiple Choice

A 5.0-kg box slides up an inclined plane at a constant speed when a 25-N force is applied to it parallel to the plane of incline. Assuming that the acceleration of gravity is 10 m/s², the coefficient of kinetic friction between the box and the incline is

A) f_k = 0.20.
B) f_k = 0.25.
C) f_k = 0.30.
D) f_k = 0.35.