Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can define elastic, inelastic and perfectly inelastic collisions using the total kinetic energy of the system. (Guide: “Two conservation questions for every collision”; Practice Q1)
- I can explain that momentum is conserved in every collision of an isolated system, whatever happens to kinetic energy. (Guide: Common misconceptions; Practice Q1(D), Q3(D))
- I can explain that individual kinetic energies may change in an elastic collision while the system total stays the same. (Guide: Worked example 2; Practice Q1)
- I can explain where the kinetic energy goes in an inelastic collision, and why total energy is still conserved. (Guide: “Inelastic collisions”; Figure 2)
Skills
- I can find the common velocity after a perfectly inelastic collision, with signed velocities. (Guide: Worked example 1; Practice Q2)
- I can classify a collision from masses and velocities by comparing kinetic energy totals. (Guide: Worked examples 2 and 3; Practice Q4)
- I can derive the fraction of kinetic energy transformed when a moving object sticks to one at rest, and use it to predict changes. (Guide: Worked example 1(c), “Comparing scenarios with the expressions”; Practice Q3)
- I can read collision data from a velocity–time graph and find a force and the centre-of-mass velocity. (Guide: Figure 1; Practice Q5)
- I can plot K_after against K_before and use its slope to test a prediction. (Guide: “Testing whether a collision is elastic”; Practice Q6)
Reasoning
- I can explain why kinetic-energy conservation must not be used across a sticky collision, and solve a two-stage problem with momentum then energy. (Practice Q7)
- I can argue that objects bouncing apart is not enough to show a collision is elastic. (Guide: Worked example 3)
- I can explain why an explosion increases a system’s kinetic energy while conserving its momentum. (Guide: “Explosions: the reverse of sticking together”)
All ticked? Move on to Topic 5.1, Rotational Kinematics, or return to the course roadmap.