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 describe work as energy transferred into or out of a chosen system, and say what a positive, negative or zero value means. (Guide: “Work is an energy transfer”)
- I can explain why a force perpendicular to the motion, such as the tension in uniform circular motion, does no work. (Guide: “The dot product and constant forces”; Practice Q2)
- I can state what makes a force conservative, name gravity and springs as examples, and name friction and air resistance as nonconservative. (Guide: “Conservative and nonconservative forces”; Practice Q3)
- I can decide when a system can be modelled as an object by comparing the motion of the point of application with the centre of mass. (Guide: “Object or system”; Practice Q6)
Calculation
- I can calculate work with the dot product, from magnitudes and angle or from components. (Guide: component example and Worked example 2; Practice Q1)
- I can integrate a variable force along a path, including the spring force −kx. (Guide: Worked example 1; Practice Q5(b))
- I can find work as the signed area under a graph of F‖ against position. (Guide: Figure 1; Practice Q4)
- I can use the work–energy theorem, with the work of every force, to find a speed. (Guide: Worked examples 1 and 2; Practice Q4(b))
- I can find the energy removed by friction as friction force times path length. (Guide: Worked example 3)
Reasoning and derivation
- I can derive the work–energy theorem from Newton’s second law using the chain rule. (Guide: “Net work and the work–energy theorem”; Practice Q5(a))
- I can show that a force is nonconservative by finding different work along two paths, or non-zero work round a loop. (Guide: Worked example 3; Practice Q7)
- I can explain where the energy comes from when a force does no work but the system still speeds up. (Practice Q6(c))
All ticked? Move on to Topic 3.3, Potential Energy, or return to the course roadmap.