hardest AP PHysics lab EVERRRRRR

[the4thcafeavenue]

now guys, i need your help. in this lab, i am making a rocket with a 2 litter soda bottle with water inside, and air will be pumped in so that rocket will fly up. i need to determine a set of equations that will describe the THRUST of my rocket as a function of TIME or MASS or both. we can use M*(delta)v=dm*Ve and Vf-Vi=Ve*ln(Mi/Mf) and whatever other equations will help. Thrust= M(dv/dt) or Ve*(dM/dt).

[Justin Lazear]

Start with Newton's second law,

F = \frac{d}{dt} mv

and keep in mind that mass is no longer constant, so you must apply the chain rule.

F = \frac{d}{dt}\left( mv\right) = v\frac{dm}{dt} + m\frac{dv}{dt}

See what you can do from there.

--J