Consider three widely separated galaxies in an expanding universe. Imagine that you are located in galaxy 1 and observe that both galaxies 2 and 3 are moving away from you. If you asked an observer in galaxy 3 to describe how galaxy 2 appears to move, what would he or she say?

The observer will say that galaxy 2 is moving away from galaxy 3 where he stands.

Explanation:

Since the galaxies are expanding, each one would move away from the others. Observers on all three galaxies have their frame of reference fixed on their own galaxies. Judging from their own galaxies, each observer will perceive the other galaxies moving away from his/or galaxy.

The observer at galaxy 3 will talk about galaxy 2 by doing is; he will say that galaxy 2 is moving far from him.

We are told that the universe is expanding and as such, the galaxies would be expanding and moving away from each other.

Since the galaxies are expanding, it means that they will be moving away from each other.

From time dilation principle, an observer at galaxy 3 will say that galaxy 2 is moving far from him.

Read more about galaxies at; link

i had this question and the answer was 3.15 miles.

martina travels from school to her mom's office. from there, she walks to school. after school, she walks to the library and then to a friends house before finally ending back at home. find martina's total distance traveled.

a) 0 miles  

b) 0.4 miles  

c) 1 mile  

d) 3.15 miles

i would say