- #1
Lawrencel2
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Homework Statement
Find the Rockets height as a function of time
It is in a constant field g. u refers to the exhaust speed and M is the initial mass.
Starts from rest. and is single stage.
Homework Equations
1) m * dv/dt= -dm/dt * u-mg
2)Show that height as t is: y(t)= u*t- 1/2*g*t^2- u*t*ln(M/m)
The Attempt at a Solution
Ok, i arrived at a function very similar to the the height but, i cannot seem to get the u*t term in the function. i get y(t)= - 1/2*g*t^2- u*t*ln(M/m)
where do i get the u*t term from? i feel like i am so close to the answer but so far away..
I integrated 1) and arrived at V(t)= u*ln(M/m)-g*t