Refer to the following information for the next three questions.
A car is racing away from a siren at 25 m/sec. The siren is emitting a frequency of 1200 hz. The air temperature is 30ºC.
Refer to the following information for the next question.
You are standing in the median between the lanes of a N-S highway, listening to five identical cars. At t = 0 sec, all five are at located 343 meters away from you and are moving as shown below. The sound from all five reach your ear one second later.
This
physlet
shows how a moving source affects the apparent frequency heard by a stationary listener.
- 30 m/s, steady speed, away from you going N
- 30 m/s, steady speed, towards you going N
- 30 m/s, steady speed, towards you going S
- 30 m/s, steady speed, away from you going S
- pulled off on the side of the road
Refer to the following information for the next three questions.
In each diagram, information about the frequencies heard by the listener are based on time.
|