Chosing appropriate letters (labels)

[Micko]

Hello,
Usually , power is labeled as P, energy as E and pressure as p. I wonder what are the alternatives? I want to use p as instantaneous power p(t) = u(t)*i(t). But yet I also want to use appropriate letter for denoting pressure.
What would you recommend? I know that alternative letter to E is W, but not sure about power and pressure.
Thanks

 

[Dr.D]

There are not enough letters available to have no overlap if your studies take you very far. You just have to live with this. If you use all of the Latin letters and all the Greek letters, that gives you 50 possibilities, but some of them are not very useful. Some, like "o" and "omicron" look too much like zero to be very useful, and there are other similar difficulties. Some folks use the Hebrew alphabet as well, but that too has limitations, particularly since it is not nearly as widely known. In the long run, you just have to deal with some degree of ambiguity.