In a car lift used in a service station, compressed air exerts a force on a smal
ID: 1477131 • Letter: I
Question
In a car lift used in a service station, compressed air exerts a force on a small piston that has a circular cross section of radius 5.23 cm. This pressure is transmitted by a liquid to a piston that has a radius of 12.7 cm.
(A) What force must the compressed air exert to lift a car weighing 14,500 N?
(B) What air pressure produces this force?
SOLVE IT
(A) What force must the compressed air exert to lift a car weighing 14,500 N?
Conceptualize Review the material about Pascal's law to understand the operation of a car lift.
Categorize This example is a substitution problem.
Solve
F1/A1 = F2/A2 for F1:
(B) What air pressure produces this force?
Use the definition of pressure to find the air pressure that produces this force:
286161 Pa
This pressure is greater than the atmospheric pressure.
__________________= N
= 3460 NExplanation / Answer
F1/A1 = F2/A2
F1 = F2*A1/F2
A1=pi*0.0523^2
A2=pi*0.127^2
F2=14500N
F1 = 14500*0.0523^2/0.127^2
F1 = 2459 N
The pressure is F1/A1 = 2459/*0.0523^2
= 286329 N/m^2
= 286329 pa.