• Rudee@lemmy.ml
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    2 days ago

    Any r/theydidthemath refugees around to calculate the amount of thrust you would receive from something like this?

    • 🍉 DrRedOctopus 🐙🍉@lemmy.world
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      2 days ago

      the questions are the specific impulse of those engines, then Delta-V.

      a mentos and coke can reach about 3m height gayser, therefore initial nozzle velocity is 7.67m/s, and a 2l bottle lasts about 2 seconds. resulting in a ISP of 0.7822 seconds.

      for comparison, the shuttle solid rocket booster has an isp of 250 seconds, a normal liquid rocket engine is about 450 seconds (the more the better).

      plugging in the weights of the Saturn 1, gives a delta V of [drumroll] 18.6 m/s… enough to accelerate a giant rocket to highway speeds.

      can we make it bigger to get to orbit? nope, the rocket equation won’t let you with that specific implied. sorry