- #1
Samurai44
- 57
- 0
Greetings ,
Many Doppler effect questions require to find the final Frequency/Wavelength. so after using the equation :
Δλ / λ = v / c or Δf / f = v / c
How can I know if the change in Frequency/Wavelength is positive or negative to calculate the final frequency or wavelength. because sometimes they add the change to initial but in others they subtract .
i know this's all related to :
* Δf= ff - fi or Δλ=λf - λi
* Source approaching: frequency increase , hence wavelength gets shorter
* Source moving away : frequency decrease , hence wavelength gets longer
Many Doppler effect questions require to find the final Frequency/Wavelength. so after using the equation :
Δλ / λ = v / c or Δf / f = v / c
How can I know if the change in Frequency/Wavelength is positive or negative to calculate the final frequency or wavelength. because sometimes they add the change to initial but in others they subtract .
i know this's all related to :
* Δf= ff - fi or Δλ=λf - λi
* Source approaching: frequency increase , hence wavelength gets shorter
* Source moving away : frequency decrease , hence wavelength gets longer