1. The problem statement, all variables and given/known data I have a circular vacuum cup. The cup has a diameter of 4.5 inches. I need to calculate the amount of pressure, in inches of mercury (Hg), that the vacuum created by the cup would have to be in order to generate 120 pounds of force on a flat object. 2. Relevant equations None given. 3. The attempt at a solution It's been years since I've had to do any math or physics, but this is what I think is correct. First, P = F/A, where P = pressure, F = force, and A=area P = 120 pounds / ((2.25)^2 * pi) = 7.55 psi Second, convert psi to Hg: 1 psi = 2.036 Hg, so 7.55*2.036 = 15.36 Hg So, what I'm hoping for here is verification that I did this correctly or someone to set me straight on this.