Astronaut Mark Uri is space-travelling from planet X to planet Y at a speed of 0.65 c.When he is precisely halfway between the planets,a distance of 1 light-hour from each,nuclear devices are detonated.The explosions are simultaneous in Mark's frame.What is the difference in 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

Question

Quizplus · Accepted Answer

According to the principle of relativity, the laws of physics should be the same for all observers regardless of their relative motion. In this case, Mark Uri is travelling at a speed of 0.65 c, which means that time appears to be passing slower for him than for an observer on Earth. This effect is known as time dilation.

However, the distance between the two explosions and Mark remains unchanged, and therefore the time it takes for the light from the explosions to reach him is also the same. Since the explosions are simultaneous in Mark's frame, he will observe them at the same time, and there will be no difference in time of arrival of the flashes.

Therefore, the correct answer is A) 0 min.

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