Answer:
Hubble measured the velocity of the movovement of galaxies by using The Doppler Effect!
Hubble's law states that galaxies located farthest from the center of the universe are moving faster than those closest to the center
Step-by-step explanation:
How do i know that the answer is correct?
I took an Assignment recently with this Same answer and the Correct answers were The Doppler effect and, Are moving faster!
Anyway I hope this Helps