1. The problem statement, all variables and given/known data In a tornado, the pressure can be 15 percent below normal atmospheric pressure. Suppose that a tornado occurred outside a door that is 195 cm high and 91 cm wide. What net force would be exerted on the door by a sudden 15 percent drop in normal atmospheric pressure? In what direction would the force be exerted? 2. Relevant equations Here lies the problem. I do no know which formula I should be using. I know that atmospheric pressure is about 1.0 x 10^5 N/m squared at sea level. Which I'm inferring is what I would use for the problem. Could someone post a formula or something? I think that's all I would need.