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 the difference between the rest frequency of a source and the frequency an observer measures. (Guide: “Rest frequency and observed frequency”)
- I can explain why the source’s own vibration does not change when it moves. (Guide: “Common misconceptions”; Practice Q1)
- I can use the travel-time argument to explain why a shrinking separation raises the observed frequency and a growing one lowers it. (Guide: “Why it happens”; Practice Q7)
- I can explain why the wave speed in a medium is not changed by the motion of the source. (Guide: “A moving source”; Practice Q5)
Skills
- I can draw a wavefront diagram for a moving source and mark where the observed frequency is higher and lower. (Guide: Figure 1, Worked example 1)
- I can use v = fλ with the crest spacing on a wavefront diagram to find the frequency at a fixed point. (Practice Q5)
- I can sketch how the frequency heard from a passing source changes with time, relative to f₀. (Guide: “A source that passes you”; Practice Q6)
- I can state the direction of the shift in wavelength for light from an approaching or receding source (blue or red shift). (Guide: “The Doppler effect for light”; Practice Q3)
Reasoning
- I can rank observed frequencies for several situations using the direction and size of the relative velocity. (Guide: Worked example 2; Practice Q2)
- I can justify why there is no shift when source and observer share the same velocity, even in a steady wind. (Guide: “What sets the size of the shift”; Practice Q7)
- I can predict how a reflected wave’s frequency changes when the reflecting object moves toward or away from the detector, and how that depends on its speed. (Practice Q4)
All ticked? Move on to Topic 14.6: Wave Interference and Standing Waves, or return to the course roadmap.