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 explain how angular momentum, angular impulse and the impulse–momentum theorem mirror their linear partners. (Guide: “The idea: a rotational version of momentum”)
- I can explain why an object moving in a straight line has angular momentum about a point off its path, and none about a point on it. (Guide: Figure 1; Practice Q1)
- I can explain why the value of angular momentum depends on the axis or point I choose, and I always state it. (Guide: Figure 1 table)
- I can state a positive sense of rotation and give every L, τ and angular impulse a sign. (Guide: “Signs, not directions”; Practice Q4)
Calculation
- I can calculate L = Iω for a rigid body. (Guide: “Angular momentum of a rigid body”)
- I can calculate L = rmv sin θ, or mv times the perpendicular distance, for a moving object about a point. (Practice Q1, Q7)
- I can compare angular impulses by multiplying torque by time, building each torque from force × lever arm. (Practice Q2)
- I can find an angular impulse from the area under a torque–time graph, including part of the area up to a chosen time. (Guide: Worked example 1; Practice Q5)
- I can use τ_net Δt = L − L₀ to find a final angular speed, remembering to include L₀. (Guide: Worked example 1; Practice Q4)
- I can read the net torque from the slope of an angular momentum–time graph. (Guide: “Reading an angular momentum–time graph”; Practice Q3)
Reasoning
- I can derive the rotational impulse–momentum theorem from τ_net = Iα for constant I. (Guide: “The rotational impulse–momentum theorem”)
- I can derive a symbolic expression, such as a stopping time or final angular speed, and check its units and limiting cases. (Guide: Worked example 2; Practice Q6)
- I can predict factors of change, such as what happens to ω when R or I is changed. (Guide: “Factors of change”; Practice Q6)
- I can justify why an object moving at constant velocity keeps the same angular momentum about any fixed point. (Practice Q7)
All ticked? Move on to Topic 6.4, Conservation of Angular Momentum, or return to the course roadmap.