# Hydralic lift

1. Jan 15, 2008

### mujadeo

1. The problem statement, all variables and given/known data

A hydraulic lift has two connected pistons with cross-sectional areas 5 cm^2 and 550 cm^2. It is filled with oil of density 520 kg/m3.

a) What mass must be placed on the small piston to support a car of mass 1500 kg at equal fluid levels?

2. Relevant equations
Is the oil density a red herring in this question???

3. The attempt at a solution

F = mg (A1/A2)

F = mg (5cm/550cm)^2

F = (1500kg)(9.81)(5cm/550cm)^2

F = 1.261N = wrong!

please help!
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Jan 15, 2008

### mgb_phys

A hydraulic system is just ratios.
In this case just the ratio of the two areas

3. Jan 15, 2008

### Shooting Star

> F = (1500kg)(9.81)(5cm/550cm)^2

??
Re-think...

4. Jan 15, 2008

### mujadeo

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook