Question

Two galaxies on opposite ends of the universe are moving away from the Earth. Each has a velocity of 200,000 km/s relative to the Earth. How fast would an observer in one of those galaxies see the other galaxy moving away? A.200,000 km/s B. between 300,000 and 400,000 km/s c. between 200,000 and 300,000 km/s D. 400,000 km/s

Answer 1

[AI-generated answer — Explain Bot]

To determine how fast an observer in one galaxy sees the other galaxy moving away, we need to consider the concept of relative velocity. Relative velocity refers to the velocity of an object as observed from another object's frame of reference.

In this scenario, we have two galaxies with a relative velocity of 200,000 km/s relative to the Earth. Now, if an observer is in one of these galaxies, they would see the other galaxy moving away from them.

To calculate the relative velocity as observed by the observer in one of the galaxies, we need to add the velocity of the second galaxy (200,000 km/s) to the velocity of the observer's galaxy relative to the Earth (200,000 km/s).

So, the total relative velocity would be 200,000 km/s + 200,000 km/s, which equals 400,000 km/s.

Therefore, the correct option would be D. 400,000 km/s.