As a locket ship moves by at 0.95c a mark is made on a stationary axis at the front end of the rocket and 9 x 10-8 s later a mark is made on the axis at the back end. The marks are found to be 100m apart. What is the rest length of the rocket? Please answer with step by step process. This is about Length contraction on Special Relativity. Thanks!

As a locket ship moves by at 0.95c a mark is made on a stationary axis at the front end of the rocket and 9 x 10-8 s later a mark is made on the axis at the back end. The marks are found to be 100m apart. What is the rest length of the rocket? Please answer with step by step process. This is about Length contraction on Special Relativity. Thanks!