I've been working on this question for quite a while and I've tried several methods with no success. I am no where near confident in my method and I was wondering if someone could point me in the right direction. The question is: A 16.5 cm diameter circular cover is placed over a 8.0 cm diameter hole that leads into an evacuated chamer. The pressure in the chamber is 22.5 kPa. How much force is required to pull the cover off? I attempted to solve by using F1/A1=F2/A2 so... I got F1=P1A1 =113.1N And 113.1N/5.027e-3m=x/2.138e-2m Isolating for x, and then F2=481N I have also tried other methods and gotten F2= 1510N, 156N, 1511N, 212N, and 665N.