In a car lift used in a service station, compressed air exerts a force on a smal
ID: 1470626 • Letter: I
Question
In a car lift used in a service station, compressed air exerts a force on a small piston of circular cross section having a radius of r1 = 5.45 cm. This pressure is transmitted by an incompressible liquid to a second piston of radius 13.6 cm.
(a) What force must the compressed air exert on the small piston in order to lift a car weighing 13,300 N? Neglect the weights of the pistons.
? N
(b) What air pressure will produce a force of that magnitude?
? Pa
(c) Show that the work done by the input and output pistons is the same.
Please explain clearly, show your work, & include a free body diagram
Explanation / Answer
Here ,
r1 = 5.45 cm
r2 = 13.6 cm
a) force , F = 13300 N
let the force on second F2
F2/(pi * r1^2) = F1/(pi * r2^2)
F2/(pi * 5.45^2) = 13300/(pi * 13.6^2)
F2 = 2135 N
the force must the compressed air exerting os 2135 N
b)
let the air pressure is P
P * pi * (0.136)^2 = force
P * pi * (0.136)^2 = 2135
P = 36763 Pa
the pressure needed is 36763 Pa
c)
as the energy is conserved ,
the work done by input and output piston is the same