Assume the same setup as in problem $2,$ i$.$e$.,$ a rocket ship passes Earth at a speed of $\frac{3}{5}c$ at $t=0$ and $t^{\text{'}}=0.$ When a clock on the rocket says $1$ hour has elapsed, the ship sends a light signal back to earth. In answering the following questions, express distances in the unit of light$-$hour