(a)
What is the minimum speed the spaceship will need for the captain to be no more than 60 years old at arrival in December 2009 the discovery was announced of a planet that may have a large amount of water and hence would be a good candidate for possible life. The planet, GJ 1214b, orbits a small star that is 42 light years from Earth. In the future we might decide to send some astronauts to explore the planet. When they arrive there, we want them to be young enough to perform tests. Suppose that the captain is 25 years old at launch time?
Explanation of Solution
Calculation:
At rest, the half-life of a certain radioisotope is
A 25-year-old captain pilots a spaceship to a planet that is
Conclusion:
Minimum speed the spaceship will need for the captain to be no more than 60 years old at arrival in December 2009 = 0.77c
(b)
How many years after launch from Earth will it be when the signal arrives at Earth as soon as the spaceship arrives at the planet, the captain has orders to send a radio signal to Earth to notify Mission Control that the trip was successful.? You can ignore acceleration times and any motion of Earth and GJ 1214b.
Explanation of Solution
Calculation:
Years after launch from Earth will it be when the signal arrives at Earth as soon as the spaceship arrives at the planet = 97 ly
Conclusion:
Years after launch from Earth will it be when the signal arrives at Earth as soon as the spaceship arrives at the planet = 97 ly
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Chapter 25 Solutions
COLLEGE PHYSICS-ACHIEVE AC (1-TERM)
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