Calculating Thrust for Rocket Weight & Altitude

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SUMMARY

This discussion focuses on calculating the thrust required for a model rocket to achieve a specific altitude, utilizing Newton's laws of motion. The fundamental equations discussed include f=ma (force equals mass times acceleration), where 'f' represents force, 'm' is mass, and 'a' is acceleration. Participants emphasize the complexity of these calculations due to the changing mass of the rocket as it burns fuel, suggesting that a good approximation can be made by considering half the weight of the fuel. Resources such as NASA's website and specific tutorials are recommended for further learning.

PREREQUISITES
  • Understanding of Newton's laws of motion
  • Basic knowledge of physics equations: f=ma, s=at, d=st
  • Familiarity with rocket dynamics and fuel consumption
  • Ability to perform basic calculations involving force, mass, and acceleration
NEXT STEPS
  • Research model rocket design principles
  • Learn about thrust-to-weight ratio calculations
  • Explore tutorials on rocket propulsion from NASA
  • Study the effects of fuel consumption on rocket performance
USEFUL FOR

Aerospace enthusiasts, model rocket builders, physics students, and anyone interested in understanding the dynamics of rocket propulsion and thrust calculations.

wolfspirit
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This is my first posting - I don't know whether its on the right section but I have a question
is there a formula to work out
how much thrust you need to get a certain weight of rocket up in the air, also for the rockets altitude?
Thanks
 
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Newton's laws of motion. Start with f=ma, s=at and d=st. How complex of a scenario are you trying to analyze?
 
Thank you. As for how complex - not very. I'm just thinking about making a model rocket and i wanted to work out how much thrust i will need to get it to a designated altitude.
Can you please just confirm what the letters mean. (f=ma, s=at and d=st) Am I right in thinking they are f=force, m=mass, a = altitude, s=speed, t=time d=distance?
Thanks again!
 
'a' is acceleration not altitude :-)
 
Unfortunately, these calculations can get quite compluicated, as the "m" keeps changing. As your rocket burns fuel, it becomes lighter, yet the thrust "f" remains the same. So, same thrust with less mass means greater acceleration.

I think (and I hope someone will correct me if I'm wrong here) you can get a fairly good approximation if you figure in only half the weight of the fuel. Since the rocket starts off lifting all pof the fuel and ends up with none, half would be the mean average of the fuel mass.

Also, if you go on NASA's website (NASA.Gov), you can find some pretty cool tutorials.
 
Thanks for that yes I can see how complicated it can get. I'll check out NASA'S website.
 

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