A student pushes a heavy crate across a warehouse floor
PHYSICS · Multi-part · CBSE · Physics · Laws of Motion · Laws of Motion
Problem
A student pushes a heavy crate across a warehouse floor. The crate initially at rest begins to speed up as the push continues.
The floor is rough, and a kinetic friction force acts opposite the direction of motion. Throughout the interval considered, the magnitude of the applied pushing force remains constant and larger than the magnitude of the kinetic friction force.
Answer the following parts about the analysis of the situation.
(a) Describe a convenient choice of coordinate axes for analyzing the motion of the crate and justify why this choice is advantageous.
(b) Draw a clearly labeled free-body diagram of the crate, listing every force acting on it. (Your diagram should not include force components.)
(c) Using only the forces identified in part (b), determine the direction of the net force on the crate relative to your chosen axes. Explain your reasoning without performing numerical calculations.
(d) Based on the net force you identified in part (c), qualitatively describe how the crate’s speed changes over time while the pushing force is applied.