A star is moving away from an observer at 1% of the speed of light.At what wavelength would the observer find an emission line that would occur at a wavelength of 6000 Angstroms if the star were at rest?
A)6060 Angstroms
B)6010 Angstroms
C)6000 Angstroms
D)5940 Angstroms

Question

Quizplus · Accepted Answer

The observed wavelength is longer due to the Doppler effect, as the star is moving away. The increase is calculated as $6000 \times 0.01 = 60$ Angstroms, making the observed wavelength $6000 + 60 = 6060$ Angstroms.

A Star Is Moving Away from an Observer at 1