Question

according to the doppler effect, what appears to happen when a light source moves further away from an observer?

• the electromagnetic waves appear more blue in color.

• the waves lengthen and frequency appears to increase.

• the electromagnetic waves appear more red in color.

• the waves compress and the frequency appears to increase.

Explanation:

When a light source moves away from an observer, the Doppler effect for light causes the wavelength of the electromagnetic waves to stretch (lengthen). Longer wavelengths in the visible spectrum shift toward the red end, a phenomenon called redshift. Blue shift occurs when the source moves closer, and moving away does not increase frequency or compress waves.

Answer:

The electromagnetic waves appear more red in color.