# Hydraulic Lift

1. Oct 5, 2008

### zuN

1. The problem statement, all variables and given/known data
The 70kg student in the figure balances a 1200kg elephant on a hydraulic lift. A second 70kg student joins the first student. How high do they lift the elephant?
diameter of the piston elephant is on = 2.0m
diameter of the piston student is on = 0.48m
The liquid inside the lift is oil, therefore rho = 900 kg/m3
Out would be elephant, In would be the students

2. Relevant equations
Fout/Fin = Aout/Ain
Fout=Aout/Ain x Fin - $$\rho$$ghAout

3. The attempt at a solution
I tried both equations
Fout/Fin = Aout/Ain
(rho x g x h x Aout) / (140 x 9.8) = (pi x 12) / (pi x 0.242)
which ended giving me h = 0.86m which was wrong.

When i tried it with the other equation i ended up with 0.44m which was wrong as well.

I am not sure if I'm using the wrong formula though so someone please give me some guidance.