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 state that a non-zero net torque changes angular velocity, with α = τ_net / I. (Guide: “From ‘is ω changing?’ to ‘how fast?’”)
- I can explain why α has the sense of the net torque, and say when a wheel speeds up or slows down. (Guide: Worked example 1; Practice Q3)
- I can derive τ = Iα for a point mass from F = ma and a_T = rα. (Guide: “Where the equation comes from”)
- I can explain why an axle force or a force through the centre gives no torque. (Guide: Figure 1; Practice Q7)
Skills
- I can predict the factor by which α changes when the net torque or rotational inertia changes, including I ∝ r² for point masses. (Guide: “Using functional dependence”; Practice Q1)
- I can compare α for objects of equal mass but different mass distribution, such as a hoop and a disk. (Guide: “Comparing scenarios”; Practice Q2)
- I can find the net torque when a friction torque acts and follow α with rotational kinematics. (Guide: Worked example 1; Practice Q4)
- I can draw separate force diagrams for a drum or pulley and a connected block. (Guide: Figure 1; Practice Q5)
- I can combine ΣF = ma, Στ = Iα and a = Rα to derive and calculate an acceleration and tensions. (Guide: Worked example 2; Practice Q5)
Reasoning
- I can explain why the tensions on the two sides of a pulley with rotational inertia differ. (Practice Q5)
- I can use an α–τ graph to find I from the slope and a friction torque from the intercept, and evaluate a claim of direct proportion. (Practice Q6)
- I can justify why the linear and rotational motion of one object are analysed separately. (Guide: “Linear and rotational analyses are separate”; Practice Q7)
All ticked? Move on to Topic 6.1, Rotational Kinetic Energy, or return to the course roadmap.