Given data
Wavelength emitted by the star (rest wavelength):
λ0=6600ÅObserved redshift (increase in wavelength):
∆λ=22ÅThe redshift implies that the star is moving away from the Earth.
Formula (for non-relativistic Doppler shift)
For light at non-relativistic speeds:
=where
v= radial speed of the source relative to the observer,
c=3×108ms−1.Substituting values
=v=3×108× v=3×108×3.33×10−3v=1.0×106ms−1v=106ms−1=10×105ms−1Direction
Since the wavelength is red shifted, the star is receding from Earth.
Answer:
Option B
Receding away from Earth with a speed of
10×105m∕s
