Question

an astronomer investigating a star determines that the light wavelengths she observes are longer than those expected to be emitted by the star.
What can be concluded about the motion of the star relative to Earth’s position?
A. The star is moving closer to Earth.
B. The star is moving away from Earth.
C. The star is accelerating faster than Earth.
D. The star is accelerating at the same speed as Earth.
WHY? _____________________________________________________________________________

Answer 1

do u know doppler effect

Answer 2

wavelengthof star light became longer than the original wavelength of the light. so the star is going away

Answer 3

u hv to know the formula of doppler