A student wishes to drag a wooden crate across a level warehouse floor at a constant…
PHYSICS · Multi-part · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A student wishes to drag a 50kg wooden crate across a level warehouse floor at a constant speed.
(a) The student pulls with a horizontal rope. If the coefficient of kinetic friction between the crate and the concrete floor is μk=0.20, calculate the magnitude of the pulling force required to keep the crate moving at constant velocity.
(b) Realizing the crate is heavy, the student instead attaches the rope so that it makes a 15∘ angle above the horizontal. Determine the magnitude of the pulling force that will now keep the crate moving at constant speed. Neglect any change in the coefficient of friction when the rope is angled.
(c) Compare your answers to parts (a) and (b). Explain physically why tilting the rope changes the required force.