1. A train traveling at a speed of 40 m/s approaches an observer at a station and sounds a 550-Hz whistle. What frequency will be heard by the observer? Assume that the sound velocity in air is 345 m/s.
2. What frequency is heard by an observer who hears the 450-Hz siren on a police car traveling at 35 m/s away from her? Assume that the velocity of sound in air is 345 m/s.
3. A car is traveling toward you at 40.0 mi/h. The car horn produces a sound at a frequency of 480 Hz. What frequency do you hear? Assume that the sound velocity in air is 1090 ft/s.
4. A car is traveling away from you at 40.0 mi/h. The car horn produces a sound at a frequency of 480 Hz. What frequency do you hear? Assume that the sound velocity in air is 1090 ft/s.