Posted by **Melissa** on Monday, June 4, 2012 at 1:12pm.

A car sounds its horn (502 Hz) as it approachs a pedestrian by the side of the road. The pedestrian has perfect pitch and determines that the sound from the horn has a frequency of 520 Hz. If the speed of sound that day was 340 m/s , how fast was the car travelling

- physics -
**Elena**, Monday, June 4, 2012 at 2:55pm
f(observed) = 520 Hz, f(source) = 502 Hz, u = 340 m/s

At source approaching

f(observed) = [v/(v-u)] •f(source),

v =[f(obs)-f(sour)] •u/ f(obs) =

= (520-502) •340/520 = 18•340/520 =

=11.77 m/s.

## Answer this Question

## Related Questions

- physics - The frequency of an ambulance's siren is 700 Hz. If a pedestrian on ...
- physics - a car sounds its horn as it travels at a steady speed of 15m/s along a...
- Physics - A train sounds its horn as it approaches an intersection. The horn can...
- physics - 1)As a sound source moves away from a stationary observer, the number ...
- physics - A car traveling at 22.1 m/s honks its horn as it directly approaches ...
- physics - 1)As a sound source moves away from a stationary observer, the number ...
- Physics - A man driving a car toward a large vertical wal sounds his horn. The ...
- Physics URGENT!!! - A train sounds its horn as it approaches an intersection. ...
- Physics URGENT!!! - A train sounds its horn as it approaches an intersection. ...
- physics - A train is moving parallel to a highway with a constant speed of 16.0 ...

More Related Questions