Two motorcycles are traveling in opposite directions at the same speed when one of the
cyclists blasts his horn, which has frequency of 544 Hz. The other cyclist hears the
frequency as 522 Hz. If the speed of sound in air is 344 m/s, what is the speed of the
motorcycles
2 answers
http://en.wikipedia.org/wiki/Doppler_effect Use that equation.
The motorcyclists are going in opposite directions, away from one another. Each has speed v and the sound speed is a. The received frequency is
522 = 544*(a-v)/(a+v)
(344-v)/(344+v) = 0.95956
344-v = 330.09 + 0.94956v
1.94956v = 13.912
v = 7.1 m/s
522 = 544*(a-v)/(a+v)
(344-v)/(344+v) = 0.95956
344-v = 330.09 + 0.94956v
1.94956v = 13.912
v = 7.1 m/s
1 answer