# Vapor Pressure Laws

1. Jun 2, 2008

### ZachWeiner

So, I'm new to astrophys, and I'm having trouble making a model because I don't think I understand an equation. It's a vapor pressure law, and it says it takes the form of

log(pressure) = A-(B/T)

T is in kelvins, A is 10.6, and B is 13500.

Apparently pressure ends up being dynes/cm^2.

So, first off, I don't know the units of A or B, or whether log is base ten or base e.

In MatLab, I'm saying pressure = 10^(A-(B/T))

Because I don't understand the equation, I don't know if that makes sense or not! Please help!

2. Jun 4, 2008

### avalonme

You can find many vapor pressure formulae (for water) here: