Regents Physics Period: Date: Homework # 8 - Doppler Effect Handout Problems: 1. At a factory, a whistle of fixed frequency is blown at constant loudness. Compare the sound waves of the whistle as heard by an employee 100 m from the factory with those heard by an employee 1 km from the factory with respect to (a) frequency and (b) loudness. 2. When workers in a car ride toward the same factory at high speed, what change takes place in the number of waves reaching them per second? (b) What effect does their motion have on the pitch of the sound they hear? 3. A driver hears the siren of an ambulance which is moving away from her. If the actual frequency of the siren is 2000 hertz, which may be the frequency heard by the driver? 1900 Hz, 2000 Hz, or 2100 Hz. Explain. 4. Light from the star Betelgeuse displays a Doppler red shift. Is Betelgeuse moving towards or away from us? Explain. 5. A policeman's stationary radar device indicates that the frequency of the radar wave reflected from a car is greater than the frequency emitted by the radar device. What does this say about the motion of the car? If the car speeds up, how will the frequency detected by the radar device change? 6. Is there a Doppler effect if the sound source and an observer are moving with the same velocity? Explain. 100% Give Feedback An