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 why a torque transfers energy only when the object turns while the torque acts. (Guide: “Torque transfers energy only when something turns”)
- I can derive W = τΔθ from the work done by a tangential force moving along an arc s = rΔθ. (Guide: “Deriving W = τΔθ”, Figure 1; Practice Q5)
- I can explain why torque and work are different quantities even though both can be written with N·m. (Guide: FAQ and misconceptions)
- I can decide whether a torque does positive, negative or zero work, including friction and forces through the axle. (Guide: “Positive, negative and zero work”; Practice Q3)
Calculation
- I can calculate the work done by a constant torque, converting revolutions or degrees to radians first. (Guide: Worked example 1; Practice Q1)
- I can find the work done by a changing torque from the area under a torque–angle graph, using rectangles, triangles and trapeziums. (Guide: Worked example 2, Figure 2; Practice Q4, Q6)
- I can use W_net = ½Iω² − ½Iω₀² to find a final angular velocity, including an object that is already spinning. (Guide: Worked example 1; Practice Q4)
- I can derive a symbolic expression, such as a stopping angle Iω₀² / (2τ_f), and predict factors of change from it. (Guide: Worked example 3; Practice Q2, Q5)
Reasoning
- I can plan an experiment that measures torque at known angles, plot the torque–angle graph with suitable scales and find the work from it. (Guide: “Planning an experiment”; Practice Q6)
- I can justify a claim comparing two spin-ups by comparing the work done, not just the torque or angular acceleration. (Practice Q7)
All ticked? Move on to Topic 6.3, Angular Momentum and Angular Impulse, or return to the course roadmap.