Question

Light is gathered from a distant star and one of the spectral lines is observed at 570 nm when it should be 400 nm. The velocity of this star is _____ km/s

Answer 1

The observed shift in the spectral line towards a longer wavelength suggests that the star is moving away from us. Using the Doppler effect formula, we can calculate the velocity of the star to be approximately 169.5 km/s.

Step-by-step explanation:

The observed shift in the spectral line towards a longer wavelength indicates that the star is moving away from us. This phenomenon is known as the Doppler effect. To calculate the velocity of the star, we can use the formula:

v = (λ - λ0) / λ0 * c

where v is the velocity of the star, λ is the observed wavelength, λ0 is the rest wavelength, and c is the speed of light.

Using the given values, we can calculate:

v = (570 nm - 400 nm) / 400 nm * 3.0 x 108 m/s

v ≈ 169.5 km/s