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 the net external force on a system equals its rate of change of momentum. (Guide: “Force is the rate of change of momentum”)
- I can define impulse, give its unit, and show that 1 N·s = 1 kg·m/s. (Guide: “Impulse”; Practice Q1)
- I can state the impulse–momentum theorem and explain that impulse points the same way as the net force. (Guide: “The impulse–momentum theorem”)
- I can show that F_net = ma follows from the theorem when mass is constant, and say why changing-mass systems are only described in words. (Guide: “Newton’s second law as a special case”)
Calculation
- I can calculate a change in momentum with signed velocities, including a rebound. (Guide: Worked example 2; Practice Q4)
- I can find an impulse from the area under a force–time graph, using rectangles and triangles. (Guide: Figure 1, Worked example 1; Practice Q2)
- I can find the net force from the slope of a momentum–time graph. (Guide: Figure 2; Practice Q5)
- I can find the force from a surface during an impact by adding the weight to the net force. (Guide: Worked example 3; Practice Q4, Q7)
Reasoning
- I can explain, with J = F_avg Δt = Δp, why a longer stopping time reduces the average force. (Guide: Worked example 3; Practice Q3)
- I can predict how the average force changes when the drop height or the stopping time changes. (Practice Q7)
- I can plan an experiment with force and motion sensors that tests the impulse–momentum theorem. (Guide: “Testing the theorem in the lab”; Practice Q6)
- I can linearise impulse and velocity data, find a mass from the slope, and use the graph to support or refute the theorem. (Practice Q6)
All ticked? Move on to Topic 4.3, Conservation of Linear Momentum, or return to the course roadmap.