The Doppler effect is used in 'speed cameras' because:

  1. it measures the vehicle's mass
  2. vehicles emit radar
  3. the frequency shift depends on the speed of the vehicle
  4. the shift depends only on colour
Answer

C) the frequency shift depends on the speed of the vehicle

Delta f propto v. SLO P-11-D-04 · Understanding

Physics MCQ · More Wave Intensity and the Doppler Effect MCQs · Practise