A Spacecraft Is Measured by an Observer on the Ground

Question 22
Short Answer

A spacecraft is measured by an observer on the ground to have a length of 53 m as it flies toward the earth with a speed 1.7 × 108 m/s.The spacecraft then lands and its length is again measured by the observer on the ground,this time while the spacecraft is at rest on the launchpad. What result does he now get for the length? (c = 3.00 × 108 m/s)