A microphone beside a runway records a steady warning tone from a helicopter. The helicopter then flies directly away from the microphone at a steady speed.
Compared with the sound recorded when the helicopter is stationary, which describes the wavelength and frequency recorded while the helicopter is flying away?
Wavelength increases; frequency decreases
Wavelength increases; frequency increases
Wavelength decreases; frequency decreases
Wavelength decreases; frequency increases
94 exam-style questions on Edexcel GCSE Physics 7.2 The Universe and red-shift, covering 7.2.1 Big Bang and Steady State theories, 7.2.2 Evidence for the Big Bang, 7.2.3 The Doppler effect and red-shift, 7.2.4 Red-shift as evidence for an expanding Universe, and 7.2.5 The CMB and the accepted model. Each one has a worked solution and a mark scheme showing where the marks go.