Hi all, I'm not a mechanical engineer, so please forgive my ignorance if this is obvious. I have a set of data that I'm working with for a piston which gives me the crank angle and internal pressure inside the cylider as the piston cranks. I've been given stroke length, cylinder bore & that the measurements were taken at 1200 RPM. I've been asked by a friend to write a MATLAB script which calculates and plots the power and the instantaneous power. However I cannot understand what the difference is between the two. I know that power can be calculated using P = F * v (from which I've half figured out that F is the force applied to the piston multiplied by the pressure and V is the velocity, which would need to be in radians per second in our case). What to do with instantaneous power has me totally stumped, though. Any help would be greatly appreciated.