Astronaut Mark Uri Is Space-Traveling from Planet X to Planet

question 48

Multiple Choice

Astronaut Mark Uri is space-traveling from planet X to planet Y at a speed of 0.65c relative to the planets, which are at rest relative to each other. When he is precisely halfway between the planets, a distance of 1.0 light-hour from each one as measured in the planet frame, nuclear devices are detonated on both planets. The explosions are simultaneous in Mark's frame. What is the difference in the time of arrival of the flashes from the explosions as observed by Mark?

• A) 0 min
• B) 180 min
• C) 90 min
• D) 360 min
• E) 113 min

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Definitions:

Renewable Energy

Energy from sources that are naturally replenishing but flow-limited, such as sunlight, wind, water currents, geothermal heat, and bioenergy.

Stored

Kept or accumulated for future use, referring to anything that can be retained or conserved for a period of time.

Compete

To strive for a goal, such as a prize or higher status, against others by overcoming challenges and obstacles.