Question

Obviously, we can make rockets to go very fast, but what is a reasonable top speed? assume that a rocket is fired from rest at a space station in deep space, where gravity is negligible. assume that c = 3.00 108 m/s.

Answer 1

I’ve answered this problem before and there were 2 parts in this problem.

The solution would be like this for this specific problem:

A. Vf = Vi + Vex*ln(Mi / Mf)
0.002 * 3e8m/s = 0 + 2000m/s * ln(Mi / Mf)
300 = ln(Mi / Mf)
1.9e130 = Mi / Mf

B. 4000m/s = 2000m/s * ln(Mi / Mf)
2 = ln(Mi / Mf)
7.389 = Mi / Mf
Mf = Mi / 7.389 = 0.135*Mi