Answer:
6.34 x 19^14 Hz
Explanation:
Wavelength, λ = 473 nm = 473 x 10^-9 m
the relation between the frequency and the wavelength is given by
v = f x λ
where, v is the velocity of light in vacuum which is equal to 3 x 10^8 m/s.
So, f = v / λ
f = ( 3 x 10^8) / ( 473 x 10^-9)
f = 6.34 x 19^14 Hz
Hope this helps. If you need clarification just ask me!
when observer and source moves relative to each other then the frequency received by the observer is different from the real frequency
This apparent change in frequency due to relative motion is known as Doppler's effect.
Here we know that

here we know that
= real frequency
v = speed of sound
= speed of observer
= speed of source
so this is known as Doppler's Effect