Question

1. a light - emitting object moving toward an observer will appear to the observer to be emitting waves that are a) unchanged b) longer than normal c) shorter than normal

Explanation:

This is based on the Doppler effect in physics. When a light - emitting object moves towards an observer, the light waves get compressed. Shorter wavelength corresponds to higher frequency in the electromagnetic spectrum. So the waves appear shorter.

Answer:

C. shorter than normal