Thursday

October 2, 2014

October 2, 2014

Posted by **Darren** on Thursday, May 5, 2011 at 3:07pm.

a. How fast must the rocket travel relative to the Earth? Give your answer as the fraction of the speed of light.

b.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?

c.How much energy is needed to accelerate the rocket to this speed?

d.The entire earth uses approximately 5*1020 Joules of energy each year. What is the ratio of you answer to part c to the total Earth's energy usage in one year?

- Physics -
**fila**, Sunday, November 18, 2012 at 11:44pmL/V=20 years

L=20V

using L= Lo/1-v2/c2 lenght contraction

20V=430/1-v

V = 0.996 c

is it right..please give right answer plz..

**Answer this Question**

**Related Questions**

Physics - In an attempt to reduce the extraordinarily long travel times for ...

8th grade math - Light travels approximately 5.87 X 10^12 miles in one year. ...

8th grade math - Light travels approximately 5.87 X 10^12 miles in one year. ...

Physics "Space Travel" - Suppose you want to go to the immense red giant ...

Math - A star is 300 light years away from Earth. If the speed of light is 3 X ...

science - Suppose that you can just barely see a certain star that is at a ...

Astronomy - The apparent brightness of a Cepheid variable star in a far-away ...

Math - The distance that light travels in 1 year (a light year) is 5.88 x 10^12 ...

physics - A certain star is 10.9 light-years away. How long would it take a ...

Physics - A rocket of 500 kg accelerates away from earth with an engine thrust ...