Hello- I have a problem with a calculation regarding a mechanical tool, so I hope that this forum section is the proper place to post this message. If not, please let me know where would be best. Some background.... In automobile mechanics, construction, etc., a torque wrench is a socket tool used to accurately apply proper torque when tightening fasteners. Occasionally there may be a need to apply more torque than a certain torque wrench can deliver. In this case, there's a simple adapter which can be added to increase the tool's torque capability -- an extender bar. An extender bar is a section of pipe or tubing of any length desired, but they all have a male drive at one end to accept a socket, and a female fitting at the other end to allow the torque wrench to be attached. The combined tool looks like this: |- Extender (length = E) -|- Torque Wrench (length = W) -| O-----------------------O---------------------------======= handle socket The calculation for the resulting torque at the socket is well known and simply multiples the overall length (E + W above) by the force which is applied at the center of the torque wrench handle. For example, suppose the torque wrench is 2 feet long (W) and the extender is also 2 feet long (E). Assume the torque wrench setting is adjusted to be 100 ft-lbs of torque. Since the torque wrench is 2 feet long (W), 50 pounds of force must be applied at the center of the torque wrench handle to produce the torque wrench setting of 100 ft-lbs. So when this 50 pound force is multiplied by the overall length of 4 feet (E + W), this results in 200 ft-lb.s of torque at the socket on the end of the extender bar. The above is easy to see and makes perfect sense, but the problem is there's another way to look at this calculation which also SEEMS to make sense, yet it's WRONG. It's hard to see why it's wrong.... though it is! Here's this (wrong) alternative calculation: Since the definition of torque is just force times distance, it sounds possible to simplify the calculation and just use the basic definition instead. So forget about the actual physical length of the torque wrench (W). If the torque wrench is set to 100 ft-lbs, that seems identical to saying that we effectively have 100 pounds of force at an effective length of 1 foot. If that's so, then adding the extender bar length of 2 feet would then yield an overall length of 3 feet. And 3 feet times the 100 pounds of force gives 300 ft-lbs of torque at the socket. Sounds good, but that's incorrect. As we know, the right answer is 200 ft-lbs. Bottom line: Where's the error in the "simplified" way of looking at this? I understand the correct way to do the calculation, but where's the fallacy in the alternate view? Can someone point out what's wrong? Help. Thanks!