At 15:23 -0400 3/27/10, Jay wrote:Okay, how about this?"let's imagine that a road crew member is shoveling dirt. ... our crew member deposits each load of dirt onto a heap about 4feet away (about one hex) from where he is digging. The 4 feet is the distance.... tada! -- we have power." 55 ft-lbs per second is 10 ST and 1 ST is 1/100th of 1hp. 1 horsepower = 745.699872 watts 1pt ST is around 7.5 watts
With one caveat, I agree. If the 4 feet is vertical distance - i.e. the dirt is being thrown up into a truck-bed 4 feet above where it's being dug out of - then the calculation is correct. Moving something perpendicular to the force being applied - like rolling a loaded railroad car on a level roadbed - doesn't count as "work" even though it's not trivial to do. The math for power is "force times (distance in the direction of the applied force) per unit time" even though it's usually abbreviated as "force times distance per time".--
I'll adjust accordingly. You ma-ma-make me ha-ah-py! Simple Jay ===== Post to the entire list by writing to tft@brainiac.com. Unsubscribe by mailing to majordomo@brainiac.com with the message body "unsubscribe tft"