I was planning on building a water-powered rocket. I also wanted to know how high my rocket might go. Could someone help me figure out, how to calculate thrust produced by a rocket engine?

  • $\begingroup$ By water powered, do you mean a rocket where compressed air pushes water out? Start by calculating the energy in the compressed air at the instant of launch. A fraction of this potential energy is what is present in the rocket when it reaches peak altitude. There will be a lot of losses also which will bring down the peak altitude from the value arrived at using the energy method. $\endgroup$
    – AJN
    Nov 24, 2021 at 0:35
  • $\begingroup$ @AJN Yes, a rocket in which compressed air pushes it water out. Can you please use some numericals in the rocket equation? Thank you in advance $\endgroup$ Nov 24, 2021 at 0:58
  • $\begingroup$ You have provided no numerical data in your question. $\endgroup$ Nov 24, 2021 at 18:31

1 Answer 1


If you know the mass flow rate q and the exhaust velocity v, the thrust f is the product of q and v.

If the engine is running in a test stand, measurement of the thrust might be easier than to measure both mass flow rate and exhaust velocity.

For the measurement of thrust look at this question.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.