An airplane traveling at v = 152 m/s emits a sound of frequency 1850 Hz. At what frequency does a stationary listener hear the sound as the plane approaches? Use 340 m/s for the speed of the sound and answer in Hz.

Isn't there a standard formula for this?

http://en.wikipedia.org/wiki/Doppler_effect

To find the frequency heard by a stationary listener as the plane approaches, we need to consider the Doppler effect. The Doppler effect describes the change in frequency of a wave observed by an observer moving relative to the source of the wave.

In this case, the observer (listener) is stationary, and the source (airplane) is moving towards the listener. The formula for the apparent frequency heard by the listener is given by:

f' = (v + v₀) / (v - vₛ) * f

Where:
- f' is the apparent frequency heard
- v is the speed of sound (given as 340 m/s)
- v₀ is the velocity of the source (airplane)
- vₛ is the velocity of the listener (assumed to be zero as the listener is stationary)
- f is the emitted frequency by the source (airplane)

Given:
- v = 152 m/s
- f = 1850 Hz
- vₛ = 0 m/s

Using the formula, we can substitute the given values into the equation:

f' = (v + v₀) / (v - vₛ) * f
f' = (340 + 152) / (340 - 0) * 1850
f' = 492 / 340 * 1850
f' ≈ 2688.235

Therefore, the frequency heard by the stationary listener as the plane approaches is approximately 2688.235 Hz.