Interactive Solution 11.35 presents one method for modeling this
problem. Multiple-Concept Example 8 also presents an approach to
problems of this kind. The hydraulic oil in a car lift has a
density of 8.13 x 10² kg/m³. The weight of
the input piston is negligible. The radii of the input piston and
output plunger are 7.31 x 10^-3 m and 0.168 m,
respectively. What input force F is needed to support the
27400-N combined weight of a car and the output plunger, when
(a) the bottom surfaces of the piston and plunger
are at the same level, and (b) the bottom surface
of the output plunger is 1.50 m above that of the input
plunger?

(a)

Number

Units

No unitsskgmm/sNN·mJPa

(b)

Number

Units

No unitsskgmm/sNN·mJPa