A photon is emitted from the surface of a massive star. Which of these will the photon NOT experience as it moves away from the star?
A) The wavelength will increase.
B) The frequency will decrease.
C) The speed will be reduced.
D) The energy will be reduced.

Question

Quizplus · Accepted Answer

Photons always travel at the speed of light in a vacuum, which is constant and does not change due to gravity. The effects of gravity on a photon escaping a massive star include redshift (increased wavelength) and reduced energy, but the speed remains constant.

A Photon Is Emitted from the Surface of a Massive