Work, Energy, and Power unit test
A test on this unit alone, marked as a percentage and a letter grade — for the test your class is actually sitting, rather than for May. Answer everything, then submit once: seeing the answer to question 3 before attempting question 4 makes the final percentage meaningless.
Work from a graph
Conservative vs non-conservative forces
Kinetic energy
Thermal energy from friction uses path length
Work done by a spring
Escape and binding energy qualitatively
Hooke's law
Power in terms of velocity
Conservation of mechanical energy condition
Energy in a pendulum
Power
Conservation of mechanical energy
Short answer 1. Define or explain: Why friction has no potential energy
3 ptsShort answer 2. Define or explain: Conservative vs nonconservative force
3 ptsShort answer 3. Define or explain: Work from a force-distance graph
3 ptsShort answer 4. Define or explain: Energy bar charts
3 ptsFree response
9 ptsA 0.40 kg block is pressed against a spring of stiffness k = 500 N/m, compressing it 0.20 m on a horizontal surface. The spring is released. The block leaves the spring at point A, slides across a rough horizontal patch of length 1.5 m (μk = 0.25) to point B, then travels up a smooth curved ramp. Use g = 10 m/s² and ignore air resistance.
Calculate the energy stored in the compressed spring and the speed of the block at point A.
Calculate the energy dissipated by friction between A and B.
Calculate the maximum vertical height the block reaches on the ramp.
The experiment is repeated with a 0.80 kg block and the same spring compression. State whether the maximum height increases, decreases, or stays the same, and justify with equations.
Explain why an energy bar chart drawn for A, for B, and for the highest point must have the same total height in every column.