# Speed needed for the ship to escape Mars, on The Martian movie

Based on the two speeds and altitudes that are presented in the movie: "The Martian" which are respectively 741 m / s and 1350m, 850 m / s and 1843 m I would like to prove with calculations whether or not it would be possible for Watney to escape mars. This is for a physics homework!

• Great question! Have you tried anything yet? Are you familliar with equations like $\Delta x = \frac{1}{2} a \Delta t^2$ and $\Delta v = a \Delta t$? Do you have any information about how many seconds the burn lasted? – uhoh Mar 12 '19 at 0:22
• I tried calculate the escape velocity but i'm not sure if it's valid because the rocket has propulsion – tomas figueiredo Mar 12 '19 at 15:51
• you can calculate the escape velocity from Mars using the equation here, and look it up in the table below it: en.wikipedia.org/wiki/Escape_velocity The hard part is finding the acceleration. Normally you have velocities at two times, but here you have velocities at two positions. – uhoh Mar 12 '19 at 15:56
• Yes I know, that's why I tried with the other formula, I was wondering if the problem is speed or fuel. By my resolution, with the speeds they present is possible, but NASA says it's impossible, but if the gravity there is "lower", it should be easier – tomas figueiredo Mar 12 '19 at 16:10
• The two equations I listed, if you square the second one, re-arrange both solving for $\Delta t$'s and set them equal to each other, you can produce a new equation that may help you solve for the acceleration. You'll still need a total time. – uhoh Mar 12 '19 at 16:24