Horsepower and Torque. Options

[DerekKim]

So I was talking to a friend this morning... 2am... I realize that I understand roughly in my head what torque and horsepower do... but was exactly does each one do... in Laman's terms.

Any help would be appreciated! Just trying to learn somethign and expand my knowledge to a better understanding.

[Mid_Engine_914]

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Force is also measured in Newtons and if you applied a force of one Newton on an object in the direction of motion to move it in a straight line for one meter, then you will have done work on the object equal to one Newton-Meter or one Joule. (The work done on an object to move it in a straight line when the force is applied in the direction of motion is W = F*d.) If this work was done over a period of one second, then the power required to do it was one Joule per second which is equal to one Watt.


If you apply a force of F lbs perpendicular to a lever arm of length d ft., then you are applying a torque equal to F*d to the arm. The circumference of a circle with radius d ft. is 2*pi*d so if the force F causes the arm to rotate one revolution, then you have done work equal to F* (2*pi*d) which after some rearranging is F*d*2*pi or Torque times 2pi. So the work done per revolution is Torque times 2 pi.
Work = (Torque*2pi) / revolution. If we have r revolutions, then the total work done is
[(Torque*2pi) / revolution] * [ r revolutions] = Torque*2pi*r. Now if these r revolutions occurred in one minute, then the Power required to perform this work was Torque*2pi*r divided by 60 seconds
= (Torque*2pi*r) / 60 s = Torque*2pi* (r / 60s) or Torque*2pi*rpm and which has units of ft*lbs /s.


And since there is one hp per 550 ft*lbs / s we have


Horsepower = [(Torque*2pi) *(rpm)] / [ (550 ft*lbs / s)] where rpm = revs/60s

Therefore Hp = Torque*rpm / 5252

[orange914]

this is engineer central, WHAT HAVE YOU DONE!!!
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