Astarship voyages to a distant planet 10 ly away. the explorers stay 3.0 yr , return at the same speed, and arrive back on earth 26 yr after they left. assume that the time needed to accelerate and decelerate is negligible. a what is the speed of the starship? b. how much time has elapsed on the astronauts' chronometers? answer in years.

14.357 years

Explanation:

Total distance travelled is 10+10 ly = 20 ly

Time they stayed on the planet is 3 years

Total time from leaving to returning is 26 years

So, time they travelled is 26-3 = 23 years

Speed of light = c

Average speed

So, elapsed time

Including 3 years stationary time we get

14.357 years

∴ Time elapsed on the astronauts' chronometers is 14.357 years

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