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 what translational kinetic energy is, give its unit in base units, and say which speed to use for a system. (Guide: “Energy of motion”)
- I can explain why kinetic energy is a scalar that is never negative, while a change in kinetic energy can be negative. (Guide: “Kinetic energy is a scalar”; Practice Q1)
- I can explain why two observers in relative motion measure different kinetic energies for the same object, and why neither is wrong. (Guide: “Kinetic energy depends on the observer”; Practice Q7(d))
Calculation
- I can calculate K from mass and velocity components in two or three dimensions. (Guide: “Kinetic energy is a scalar”; Practice Q1)
- I can predict the factor by which K changes when mass and speed both change. (Guide: factor-of-change table; Practice Q2)
- I can find K(t) from a position or velocity function, and find its greatest value on an interval, including at an end point. (Guide: Worked example 1; Practice Q4)
- I can use dK/dt = m v_x a_x to find the rate of change of K and decide whether K is rising or falling. (Guide: “How K changes with time”; Practice Q4(b))
- I can calculate K and ΔK in a moving frame using the relative velocity v − u. (Guide: Worked example 3; Practice Q7)
Reasoning and representations
- I can sketch K against v, v², m, t and x, and justify each shape from K = ½mv². (Guide: graph shapes; Practice Q3)
- I can sketch K against t for a projectile and explain why its minimum is ½mv_x², not zero. (Guide: Worked example 2 and Figure 1; Practice Q5)
- I can choose a graph that turns kinetic-energy data into a straight line and use its gradient to test a claim. (Practice Q6)
All ticked? Move on to Topic 3.2, Work, or return to the course roadmap.