I am a student at the University of Delaware, working for the Disaster Research Center under grant from the National Science Foundation. My project has me analyzing building collapses and rubble/debris pile structure. I have been loaned a program by the Livermore Laboratory called Cheetah which calculates explosive pressures. This program has been unbelievably useful but the output for particular data is given to me in energy (Kg/cc) and I need it in a pressure form to calculate the pressures acting on the structure. How can I convert the energy to pressure? Remember this is acting on a structure and is not contained in a specific volume other than the container that the device is located in (which disintegrates upon initial reaction) and is not moving the entire object (so calculating the amount of work being done is a no go). Thanks for any help you can give me.