After all this recent talk of torque and power I figure I can post my stupid question of the week: How does torque relate to inertia? Say I have a nice balanced wheel that I want to spin. I can calculate the moment of inertia but I'm too old to remember how to figure out how much torque and/or power I need to over come the inertia (and friction) to get it going. I got stalled here in dimensional analysis: moment of inertia == kg·m² energy (joules) == kg·m²/s² (Newton-meters) torque == joules/radian == kg·m²/s² (same as energy but through X degrees of rotation) From wiki: A torque of 1 N·m applied through a full revolution will require an energy of exactly 2(pi) joules. So, now ignoring friction, can I figure that the driving torque just influences the acceleration? And then it's only friction that keeps my wheel from spinning when the motor is too small?