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Doppler Shift Calculator
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Doppler Shift (or Doppler Effect) is the change in frequency of the a wave observed when the observer is in motion relative to the source of the wave.

Doppler Shift Formula -
$\lambda_{f} = \frac{v -u_{s}}{f_{0}}$
Where, $\lambda_{f}$ is the 'Wavelength in Front of a Moving Source', v is the 'Wave Velocity', $u_{s}$ is the source velocity, ${f_{0}}$ is the source frequency.

Doppler Shift Calculator (Doppler Effect Calculator) is an online tool for calculating values of the unknown parameters in the Doppler Shift Formula provided other parameters are known.

## Step by Step Calculation

Step 1 :

Doppler Effect is the change in frequency and wavelength of a wave for an observer moving relative to the source of the waves.

Formula:

Wavelength in Front of a Moving Source:

λf = (v - us) / f0

Wave Velocity:

v = (λf * f0) + us

Source Velocity:

us = v - (λf * f0)

Source Frequency:

f0 = (v - us) / λf

Step 2 :

State the equation you plan to use and plug in the values.

## Example Problems

1. ### A train passes a passenger platform at a speed 92 m/s of wave velocity with moving source 2.6 m. The horn sounds at 32 Hz. Calculate the source velocity?

Step 1 :

The given:

Wavelength in Front of a Moving Source (λf) = 2.6 m.

Wave Velocity (v) = 92 m/s

Source frequency (f0) =32 Hz.

Source velocity (us) = ?

Step 2 :

Plug the values in the formula.

Source Velocity:

us = v - λf * f0 .

us = 920 - (2.6 * 320)

us = 8.800 Hz

2. ### A train passes a passenger platform at a speed of 40 m/s. The horn sounds at 320 Hz. What frequency is heard by a person on the platform as the train approaches?

Step 1 :

The given:

where λf = 220 Hz
v = 340 m/s
us = +40 towards

Step 2 :

Plug the values in the formula.

Source Frequency:

f0 = (v - us) / λf

f0 = (340 - (+40)) / 220

f0 = (340 - 40) / 220

f0 = 300 / 220