Acar approaches you with its horn blowing. the observed frequency is 503.7 hz. assume the speed of sound is 1100 ft/s. the car's horn has a frequency of 450 hz. how fast is the car going? express your answer in mph.

1420

79.8

117

Answer

79.8 miles per hours fast is the car going.

Formula

By using the dopplers effect. (When source is approching .)

As given

A car approaches you with its horn blowing.

The observed frequency is 503.7 Hz.

The speed of sound is 1100 ft/s .

The car's horn has a frequency of 450 Hz.

i.e

v = 1100 ft/s

Put in the above formula

Now convert 117.3 ft per second into miles per hours.

117.3 feet per second = 79.8 miles per hours (Approx)

Thus

Therefore the 79.8 miles per hours fast is the car going.

magnitude and direction

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.