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Old 12-06-2012, 05:55 AM
JimD1 JimD1 is offline
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I didn't read the whole thing but it seems OK. There is a far easier explanation of the two terms, however. Torque is just rotational force. It takes torque to spin the wheels against load. As long as you have more torque than the resistance, the vehicle moves. An 18 wheeler needs a lot of torque to get the load moving. The diesel engines they use have many times more torque than they have hp.

To accelerate quickly we need to do work quickly. In physics, work is defined as force times distance. The rate at which work is done is power. Our electric companies measure power in watts and kilowatts (thousands of watts). Watts and hp both measure power. 1 horsepower is defined as 33,000 lb-ft/min and is equivilent to almost 746W.

It makes a lot of sense to me that what makes us accelerate more quickly is not force but the rate at which work is done. That is why hp is more important than torque for acceleration.

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