> Average velocity = 60rpm > Average torque = (10 + 50 + 10 + 50) / 4 = 30TU= > Power = 60rpm x 30TU = 1,800 power units > However, if you calculate the power for each time sample (hence account for the different velocity recorded during each sample), then: > > Power = (62x10 + 58x50 + 62x10 + 58x50) / 4 = 1,760 power units Help me get my head around this. I know the first is correct for power around an axis. The second is incorrect and is 40 power units under. If I do this Power = (58x10 + 62x50 + 58x10 + 62x50)/4 = 1,840 power units or 40 over. So why? It feels like the reason is just at the edge of my brain. Somewhere in school I must have learned the answer.