1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Hydraulic Lift equilibrium

  1. Apr 9, 2008 #1
    1. The problem statement, all variables and given/known data

    A hydraulic lift has two connected pistons with cross-sectional areas 25 cm2 and 700 cm2. It is filled with oil of density 570 kg/m3.

    a) What mass must be placed on the small piston to support a car of mass 1300 kg at equal fluid levels? (answer: 46.4kg)

    b) With the lift in balance with equal fluid levels, a person of mass 70 kg gets into the car. What is the equilibrium height difference in the fluid levels in the pistons? (answer: 1.77m)

    c) How much did the height of the car drop when the person got in the car? HELP!

    3. The attempt at a solution

    I know that the fluid is incompressible therefore the volume is conserved. I also know that the height changed is proportional to the area of each of the pistons. I know that A1*d1=A2*d2 where d1 is the distance piston 1 is pushed down and the volume is A1 that flowed into the piston.

    Where I am confused is how do we relate the weight to the change in height.

    Any help would greatly be appreciated!
  2. jcsd
  3. Apr 9, 2008 #2
    If I say : the difference in fluid heights provides a weight that balance with that of the car.
    Does that help you in understanding their relations?:smile:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Hydraulic Lift equilibrium Date
Lifting a car using a hydraulic lift Aug 3, 2013
Pascal's principle hydraulic lift with torque involved Sep 10, 2012
Hydraulic Lift Jan 10, 2011
Hydraulic lift Jul 19, 2010
Hydraulic Lift Problem. Dec 9, 2009