Calculating pressure given dia. and pounds

[togo]

Homework Statement

the hydraulic lift for an automobile service garage has a cylinder with a diameter of 8 inches. What pressure must the oil have to be able to lift 6000 lbs?

Homework Equations

f=pa
area = pi(r^2)

The Attempt at a Solution

6000 lbs = 26 688 Newtons

8 inches = 3.14 x 16 = 50.265

26 688/50.265 = 530.9 psi (should be 119 psi)

 

[PhanthomJay]

Homework Statement

the hydraulic lift for an automobile service garage has a cylinder with a diameter of 8 inches. What pressure must the oil have to be able to lift 6000 lbs?

Homework Equations

f=pa
area = pi(r^2)

The Attempt at a Solution

6000 lbs = 26 688 Newtons

do not convert...leave in pounds of force

8 inches = 3.14 x 16 = 50.265

units...A = 50.265 in^2

26 688/50.265 = 530.9 psi (should be 119 psi)

If the problem is given in units of inches and pounds, do not convert pounds to Newtons.

 

[togo]

thanks