Two golf carts have horns that emit sound with a frequency of 394 Hz. The golf carts are traveling toward one another, each traveling with a speed of 9.5 m/s with respect to the ground. If one of the drivers sounds her horn, what frequency does the other driver hear? The speed of sound at the golf course is 345 m/s.

394 Hz

Explanation: this is a question under Doppler effect.

The mathematical equation that defines a Doppler effect is given below as

fo = {c+ vo/ c - vs} × f

Where fo = frequency observed =?

c = speed of sound = 345 m/s

vo = velocity of observer relative to source = 9.5m/s

vs = velocity of source relative to observer = - 9.5 m/s ( the negative sign is as a result of the fact that the observer and the source are moving in opposite direction to each other)

f = frequency of sound by source = 394 Hz.

By substituting the parameters, we have that

fo = {345 + 9.5/ 345 - (-9.5)} × 394

fo = (345 +9.5/ 345 + 9.5) × 394

fo = (354.5/354.5) × 394

fo = 1 × 394 = 394 Hz

the doppler effect is used by weather forecasters to measure 

moving clouds