In an attempt to reduce the extraordinarily long travel times for voyaging to distant stars, some people have suggested traveling at close to the speed of light. Suppose you wish to visit a star which is 410 ly away, and that you want your 24000 kg rocket to move so fast that you only age 20 years during the round trip.
a. How fast must the rocket travel relative to the Earth? Give your answer as the fraction of the speed of light.
0.999702691
b. As a check of your answer in part a, subtract your answer from 1 and input the result here.
0.000297309
c. Assuming your turn-around time is near zero when you reach the star, how long does your trip take according to your friends and family back on Earth? (you can use y for years)
820.243866 yr
d. How much energy is needed to accelerate the rocket to this speed?
e. The entire earth uses approximately 5*1020 Joules of energy each year. What is the ratio of you answer to part d to the total Earth's energy usage in one year?
I can't figure out part d and e
1 answer
How do you get these answers?
1 answer