Question

10. Light emitted from an object in the direction opposite that of the object's motion would

1. be shifted toward the red end of the spectrum
2. have a shortened wavelength
3. be dimmed
4. look the same as light emitted from a stationary object
5. be brightened

Answer 1

Light moving in the opposite direction of an object's motion would experience a redshift, causing the wavelength to increase due to the relativistic Doppler effect.

Step-by-step explanation:

Light emitted from an object in the direction opposite that of the object's motion would be shifted toward the red end of the spectrum. This is due to the relativistic Doppler effect, which states that the observed wavelength of electromagnetic radiation is longer when the source moves away from the observer. Furthermore, the speed of light remains constant, so when an object moves away from the observer, the light waves seem to stretch out, leading to a longer wavelength and a redshift. Essentially, as the object moves away, each wave crest has a bit more distance to cover to reach the observer, thus increasing the wavelength compared to if the object was stationary.