# Velocity required to reach star in 10 onboard years

1. Feb 3, 2010

### alanthreonus

1. The problem statement, all variables and given/known data

You wish to travel to the Pleiades (at a distance of 130 pc) in 10 years, according to the clock
that you carry. How fast do you have to travel to accomplish this (express the velocity as a
fraction of speed of light, v/c)?

2. Relevant equations

$$\Delta T = \gamma \Delta T_0$$

3. The attempt at a solution

I've been stuck on this for hours, and I really don't know how I'm supposed to set this up. If someone could just help me set it up, I can do all the calculations myself.

2. Feb 3, 2010

### ideasrule

d=vt. You know t=10 years. d can be found via the length contraction formula: to an onboard observer, the distance to the Pleiades seems contracted by a factor of gamma.