Practice!

Sample Problem

A clock ticks at rest in space. A spaceship passes it at 1.8 × 108 m/s. How long does the spaceship perceive the clock to tick for one minute? The speed of light in a vacuum is 3.00 × 108 m/s

Solution

We can use the formula:

In this case, t0 = 60 s. v = 1.8 × 108m/s. 

Thus,  s