bottle rocket

[rocketman1555]

kinetic energy = .5*mass*velocity squared

potential energy = mass*gravity*height (this is gravitational potential energy, which is what you should need to use)

plug those variables into the equations, and figure it out from there

[andrewwski]

And the maximum gravitational potential energy will equal the maximum kinetic energy.

[rocketman1555]

yeah, and the kinetic energy and potential energy combined will always equal the maximum kinetic energy

[andrewwski]

...or the maximum potential energy.

[zorbak5044]

no thats not what i mean. i need to know what it is not how much it is.

[rocketman1555]

potential energy is how much chance there could be energy, the potential for something to have energy, so its the highest at the peak of the flight

kinetic energy is the energy something has while it is moving

you'll get better definitions from google

[Frosty Phoenix]

I don't have my rules handy so I ask what are the technical stipulations on the actual bottles? For instance do they have to have the brand name of soda on them? I ask because I recently ordered about 30 soda class generic one liters but I need to know if I should strive for an branded bottle for competition rather and use my stock for trial and error.

If anyone is interested in finding my bottle resource just ask. Any help is appreciated.

[Flavorflav]

I would contact your tournament coordinator to check. If they are soda class it shouldn't be a problem, but they will want some kind of documentation and they might not accept anything other than a label.

[Frosty Phoenix]

Thanks mate. Hopefully it will come with some sort of certification or I'll just try to use them for practice.

[captbilly]

And the maximum gravitational potential energy will equal the maximum kinetic energy.

The maximum potential energy will not equal the kinetic energy because the rocket will be significantly slowed by drag. In a vacuum, and with no other forces acting on the rocket (besides gravity) you would expect the kinetic energy at end of thrust to be equal to the potential energy at maximum height. Even in a vacuum there are issues because the impulse (thrust x time) is not instantainious, so maximum kinetic energy (maximum velocity) takes places when the rocket already has significant potential energy (height)