- #1

harujina

- 77

- 1

## Homework Statement

A fire truck emitting a 450 Hz signal passes by a stationary detector.

The difference in frequency measured by the detector is 58 Hz.

If the speed of sound is 345 m/s, how fast is the fire truck moving?

## Homework Equations

frequency of observer = (velocity of sound + velocity of detector / velocity of sound + velocity of source) f0

## The Attempt at a Solution

f obs (frequency of observer) = 450 Hz + 58 Hz = 508 Hz

v sound (velocity of sound) = 345 m/s

v detector = 0

f0 (frequency of source) = 450 Hz

v source = ?

How would I solve for velocity of source? I tried plugging all of the above variables into the equation and isolating the variable but I got a totally wrong answer and I'm not sure why.