- #1
Abid Rizvi
- 20
- 0
Homework Statement
The first stage of a space vehicle consumed fuel and oxidizer at the rate of 1.60
Homework Equations
Momentum = mv
The Attempt at a Solution
So I tried to use math logic, but I'm not sure if its even logical...
Mi = initial mass of rocket
Vi = initial velocity of rocket (0)
Ve = velocity of exhaust stuff
dV = change in velocity
dM = change in mass of rocket
dm = change in mass of stuff expelled
dM = - dm
(Mi+dM)(Vi+dV) + Vedm = 0
(Mi+dM)(Vi+dV) - VedM = 0
MiVi + VidM +MidV+dMdV - VedM
Vi = 0, so
MidV+dMdV = VedM
multiply everything by (1/dt):
Mi*dv/dt + dM*dV/dt = Ve*dM/dt
solving for since acceleration = dv/dt, solving for dv/dt gets:
a = (Ve*dM/dt)/(Mi+dM) = -16.4.
It cannot be a negative acceleration so obviously something is wrong...