How Fast Is the Spaceship Traveling Relative to Earth in Terms of c?

[map7s]

Homework Statement

As measured in Earth's frame of reference, two planets are 491,000 km apart. A spaceship flies from one planet to the other with a constant velocity, and the clocks on the ship show that the trip lasts only 1.10 s. How fast is the ship traveling? (Enter your answer to 4 significant figures and in terms of c.)

Homework Equations

I tried using the equation delta t=d/v and converting the km to m, but that seemed way to easy...and I got the wrong answer. Then I tried delta t=delta t o / sqrt(1-v^2/c^2), but I wasn't sure what to plug in for the variables. Assuming that I am now on the right path, would I put in 1.1 for delta t? Would I even need anything for delta t o ?

 

[member 553083]

What about for d, would I put in 491,000?The Attempt at a SolutionI tried delta t=delta t o / sqrt(1-v^2/c^2), with delta t o =1.1, d=491,000 and v unknown. Solving for v, I got 4.7*10^6 m/s. Converting to c, I got 0.015 c.