This means that the observer will measure the length of the object to be 0.436 times its proper length.
L' = L / 2.29 = 0.436L
where t' is the time measured by the astronaut and t is the time measured by the observer on Earth. Arthur Beiser Modern Physics Solutions Of Chapter 2 Pdf
This means that the astronaut will experience time passing 1.67 times slower than the observer on Earth. This means that the observer will measure the
L' = L / γ
Problem 2.10 asks students to calculate the length contraction factor for an object moving at 0.9c relative to an observer. The length contraction factor is given by: Arthur Beiser Modern Physics Solutions Of Chapter 2 Pdf
where v is the relative velocity between two observers and c is the speed of light.