Hello Michael and everyone else who replied: I obviously need to do more research into this. Thanks for the reponses. Special thanks to Michael for informing me on how lost I am. :) Regards, Donovan Parks > Donovan Parks wrote: > >I have a 1 HP motor (= 0.75kW = 553 foot lbs/sec) and need to know how much > >force it can exert. I am looking for a 'best case' estimate - that is, > >what > >is the most force it can exert if everything were ideal. What I am > >thinking, is that if I have a load cell fixed to a wall then what will it > >read. > > Power is the *rate* at which the motor delivers energy: 750W means > the motor can do 750 joules of work every second. If you like > analogies, power is to energy as speed is to position; it is the > rate at which it changes. So, if we know your motor can deliver > 750W of mechanical power, we know the rate at which it can do > work. How much force is this? Unfortunately, there is not a > straightforward answer to this question: it depends on the system > your motor is doing work on. If, for example, you deliver work > to a frictionless test particle of mass m, initially at rest, > then the instantaneous force at time t is sqrt(Pm/2t), where P > is the power of the motor (750W in your case), ignoring any > nonconservative losses (friction, air resistance, mechanical > inefficiency, etc.). As for the force the motor can exert on a > wall, if you think about it for a second, you'll see it depends on > the setup. For example, if you attach a long swing-arm to the > shaft of the motor, then clearly it will deliver more force at the > end of the arm than if you use a short one. > > In real life, motors are usually rated by giving the power delivered > at some particular rotation speed. You can use this number to > compute the torque the motor can produce at the given rotation > speed. Is that what you want? If so, the formula is > torque = P/w, where w (usually written as the Greek lower-case > omega) is the rotational velocity. If you have P in watts and > w in radians/second, then the torque will come out in Newton-meters > (Nm). > > I'm sorry to give such a long-winded, unsatisfying answer, but > unfortunately your question is not well-posed. > > Michael V > > Thank you for reading my little posting. > > > _________________________________________________________________ > Join the world s largest e-mail service with MSN Hotmail. > http://www.hotmail.com > > -- > http://www.piclist.com hint: To leave the PICList > mailto:piclist-unsubscribe-request@mitvma.mit.edu > > -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu