Calculations wise you will need to know how do work the suvat equations and a couple of other things but only really at a basic level. What more people struggle on is the explanations and theory, so just make sure you can describe gas laws using the kinetic model and various other more theoretical things.
Things haven't changed since Meteorshower posted. Be able to use the suvat equations, understand the difference between vectors and scalars, be able to work out vectors/scalars, and be able to explain things like the gas laws. Understand forces and know Newton's three laws of motion. You should make sure that you can explain buoyancy, too.