The observed shift in wavelength \( \Delta \lambda = 6300 - 6000 = 300 \, \text{Å} \) is due to the Doppler effect.
The formula for the Doppler shift in wavelength for light is:
\( \Delta \lambda = \frac{v}{c} \lambda \)
where \( v \) is the velocity of the galaxy,
\( c \) is the speed of light, and
\( \lambda \) is the initial wavelength.
Substituting the known values, we calculate the speed of the galaxy as 500 km/s.
A source of sound is moving away from a stationary observer with constant velocity 40 m/s. Find frequency heard by observer, if original frequency of source is 400 Hz and speed of sound in air is 360 m/s