In an attempt to reduce the extraordinarilylong travel times for voyaging to distant stars, some people havesuggested traveling at close to the speed of light. Suppose youwish to visit the red giant star Betelgeuse, which is 430 ly away,and that you want your 20,000 kg rocket to move so fast that youage only 20 years during the round trip.
a. How fast must the rocket travel relative to earth?
b. How much energy is needed to accelerate the rocket to thisspeed?
c. Compare this amount of energy to the total energy used by theUnited States in the year 2005, which was roughly 1.0 ×1020 J.