PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics
Problem
A 12kg crate initially rests on a warehouse floor. A rope attached to the crate is pulled with a constant tension of 60N at an angle of 25∘ above the horizontal, as shown in the verbal description. The floor–crate interaction is characterized by a coefficient of static friction of 0.55 and a coefficient of kinetic friction of 0.42.
(a) Resolve the applied tension into horizontal and vertical components.
(b) Determine the normal force exerted on the crate while the rope is being pulled.
(c) Calculate the maximum possible static friction force acting on the crate.
(d) Decide whether the crate remains at rest or begins to slide. Provide quantitative justification.
(e) If the crate does not move under the 60N pull, find the minimum tension (applied at the same 25∘ angle) that would just start the crate moving. If the crate does move, instead calculate its acceleration after it starts sliding.