CK-12-Physics - Intermediate

12.3. Pascal’s Law http://www.ck12.org

FIGURE 12.12

If we wish to raise a 9,000 Newton car by 10 centimeters, it requires 900 joules of energy.

W=F x= ( 9 ,000 N)( 0 .10 m) =900 J

Therefore, we will have to move the narrow piston nine times farther than the distance that the wide piston rises. By

the Law of Energy Conservation (assuming no energy is transformed into heat by friction):

Ei=Ef → Win put=Wout put

( 1 ,000 N)( 0 .90 m) = ( 9 ,000 N)( 0 .10 m)

http://demonstrations.wolfram.com/PascalsPrinciple/

Check Your Understanding

The input force of a hydraulic lift is 800 Newtons and the output force is 16,000 Newtons. What is the ratioAAoutin?

Answer:

Aout

Ain

=

Fout

Fin

=

16 ,000 N

800 N

= 20

.