>>14031510Mass does not exert a force. Mass resists changes in acceleration. If you are in empty space without a medium, mass will still resist acceleration. An astronaut can throw his backpack and travel to the moon eventually.
Pressure is a force across an area. 1 psi on a knife edge will kill you. 1 psi on an iPhone won't crease your pants. Pressure also accumulates. 3 psi of water on a 40' x 16' basement wall means tons of water that will collapse a home.
Look to statistical mechanics for a general view of pressure. You have something. It has a state. Inside it are microstates. They are not independent. For insides, you assign dimensionless probability. What's the likelihood I will find a microstate, such as a collision or heat turning into work, at this energy level? Pressure, along with temperature and amount, are the external environmental factors needed for that state which is a probability of microstates.
