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? (1 point)
Responses
between 300,000 and 400,000 km/s
between 300,000 and 400,000 km/s
400,000 km/s
400,000 km/s
200,000 km/s
200,000 km/s
between 200,000 and 300,000 km/s
between 300,000 and 400,000 km/s
To determine how fast an observer in one of the galaxies would see the other galaxy moving away, we need to consider the concept of relative velocity. The relative velocity between two objects is the difference in their velocities.
In this case, the two galaxies are moving away from the Earth with a velocity of 200,000 km/s each. Since they are moving in opposite directions, the relative velocity would be the sum of their individual velocities.
Therefore, the observer in one of the galaxies would see the other galaxy moving away at a speed of 400,000 km/s.
So the correct answer is: 400,000 km/s
To determine how fast an observer in one of the galaxies would see the other galaxy moving away, we need to take into account the concept of relative velocity.
Relative velocity is the velocity of an object or observer as seen from the point of view of another object or observer. In this case, the observer in one galaxy is observing the motion of the other galaxy.
Given that each galaxy has a velocity of 200,000 km/s relative to the Earth, we need to find the relative velocity between the two galaxies.
To do this, we can simply add or subtract the velocities depending on the direction of the motion. Since the galaxies are moving away from the Earth in opposite directions, we need to subtract the velocities.
So, the relative velocity between the galaxies would be:
200,000 km/s - 200,000 km/s = 0 km/s
Therefore, an observer in one of the galaxies would see the other galaxy moving away with a speed of 0 km/s.