Question 3a) When sound travels from air into water, does the frequency of the wave change? The speed? The wavelength? Explain your reasoning. b) What do you understand by Doppler's effect? c) A police car chases a speeder along a straight road; the police car and the speeder move at 140 km/h and 160 km/h, respectively. The siren on the police's car produces sound at a frequency of 500 Hz. What is the Doppler shift in the frequency heard by the speeder? [Speed of sound in air! 340 m/s]

Question 3a) When sound travels from air into water, does the frequency of the wave change? The speed? The wavelength? Explain your reasoning. b) What do you understand by Doppler's effect? c) A police car chases a speeder along a straight road; the police car and the speeder move at 140 km/h and 160 km/h, respectively. The siren on the police's car produces sound at a frequency of 500 Hz. What is the Doppler shift in the frequency heard by the speeder? [Speed of sound in air! 340 m/s]