QUOTE=Hammerhead;4001370]A light bulb has no horsepower. The formula you are referring to, which is the relationship between watts and horsepower is for electric motors, not light bulbs. [/QUOTE]
This is ludicrous.
A light bulb has no horsepower. The formula you are referring to, which is the relationship between watts and horsepower is for electric motors, not light bulbs. Torque is a factor in any calculation of horsepower. Basic physics.
When you torque a bolt or nut with a torque wrench, as you reach the proper torque, you stop pulling the wrench harder and hold it. This is a simple example of torque without motion. Horsepower needs motion (rotation) to exist. Unless your horses are resting.
Power is power. HP is work done per unit time, just like Watts or even Joules per second (I.e. power). These arenít special equations only applicable to electric motors. In fact, this may blow your mind, but as you do work over time (like walk upstairs), you are creating HP (or Watts, if you prefer). Crazy, right??
A light bulb uses horsepower or Watts or whatever units you prefer. This is like saying lbs (pounds mass) arenít weight, only kilograms are weight. Watts are power and HP is power. They both refer to work per unit time.
Some equations for you:
Work = force x distance
Power = (force x distance)/time = work/time
You are right that torque doesnít require rotation to exist...
We are getting off topic so letís try another example. I have a 1HP electric motor lifting an elevator weighing 1000kg. How fast can I lift the elevator? How much torque do I need?
Again, you will see that torque doesnít show up in any of the equations.
I hate to pull this card, but I should mention that I have a graduate degree in engineering and design these systems daily. Of course this doesnít mean I canít be wrong but hopefully it gives me some credibility :-)