Car jack efficiency: 3000 N load, 10 cm lift, 1200 N input over 30 cm

[roxxyroxx]

Physics 11 help??!

Homework Statement

a car jack applies a force of 3000N to lift one side of a car a distance of 10 cm. in order to accomplish this the person using the jack needed to apply a force of 1200N to the handle moving it 30 cm. what is the jack's efficiency?

Homework Equations

eff = (mgh/f*d) x 100%

The Attempt at a Solution

idk where 2 start??

 

[Delphi51]

Write the formula. Replace each letter with the appropriate number.