h1a8: Power basically is how fast can you do the work. If you accelerate a mass over a given distance, you can do it slow so it takes an hour, or you can get it done in a second. Apply more force to do it faster (mass = force X acceleration). You'll get the work done either way, but with more force you get it done faster. Think if you and another guy wanted to load a bunch of 40 lb dog food bags into the back of a pickup truck. You could take all day to do it, or you could do it fast if you were stronger (able to exert more force). Same on accelerating a car to 55 MPH. You could take 5 seconds to do it in a powerful car, or 15 seconds in a car with less horsepower. Time is the new variable when we talk about power. Time is of the essence! Seriously, it is in a lot of physics applications, and real life stuff too. You'll notice that
Physics is cool dude. I took it in high school and college too. I'm a Doctor of Chiropractic (never told anybody here before, although it doesn't make me any better in comic studies!)
h1a8
The VulcanData
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quote: (post)
Originally posted by Soljer
Power: The amount of work performed per unit time.
To be honest with you Power is one of the only things in Physics that I don't truly understand (theoretically). I can do the Physics problems involving Power very easily though. Maybe with variable forces then power might make sense. But with constant forces I quite don't understand Power because I see that the change in Kinetic energy is equal to work done which in turn equals Force x Distance. But Force is equal to Mass x Acceleration. So this means that since Kinetic energy is directly proportional to acceleration then it has the same meaning as power (because work per unit time can be derived from acceleration and mass alone).
For example, if I accelerate an object of mass M from rest with constant force and for t seconds then the distance the object traveled can be calculated using force/mass=acceleration and then plugging the found acceleration into d=1/2at^2. So now I know Force and Distance and can find the work done. Also I know the time it took to do the work (which was t) and thus can calculate power. So power and work are really the same thing in disguise.
Last edited by h1a8 on Mar 14th, 2008 at 03:07 PM
