What is the difference between power and torque? Why is each important?

Answer 1

Certain electric motors can be operated for very short test periods with locked rotors (the rotors cannot turn). In this condition the motor can develop perhaps maximum torgue (the force tending to rotate the motor) but is delivering no "power" because nothing is moving. The motor is consuming electric power but is doing no work. When the rotor is released it can turn and deliver power. The horsepower rating of the motor is actually a old comparison of the ability of a living horse to move (lift) a given weight a given distance in a given time. Either a horse or an electric motor can be connected to a cable and pulley to lift a heavy load.

The gasoline motor in a car develops torque and when the clutch or automatic transmission permits the engine to move the car it develops power.

Work results when a force moves a load a distance and power is the rate of work. Torque results when a force is applied to a lever (or the handwheel of a large valve). Work is produced when the torque moves a load and power (again) is the rate of work.

Answer 2

Engines don’t make horsepower; they convert fuel into torque. Torque is the twisting force imparted to the crank flange and then transmitted to the transmission and the rest of the drivetrain. To some degree torque is the grunt that gets things moving, and horsepower is the force that keeps things moving.
Power is torque multiplied by engine speed to produce a measurement of the engine's ability to do work over a given period of time.
Torque is the static measurement of how much work an engine does, while power is a measure of how fast the work is being done. Since horsepower is calculated from torque, what we are all seeking is the greatest-possible torque value over the broadest-possible rpm range. Horsepower will follow suit, and it will fall in the engine speed range dictated by the many factors that affect the torque curve.

Answer 3

I'll assume you are refereing to cars so ill give it my best shot power is measured in brake horses (Bhp, horses being the power output of one standard horse, as deduced by Sir Isaac Newton) this is measure of how much energy it would take to stop a vehichle at its maximum power output, this is the engines power output.
Torque is the "pushing power" of the engine and is measured in ft/lbs in the US. It is how the power of the engine applied though the gears.

A more simple explaination would be a spanner and a bolt. You are trying to tighten a bolt, you have a power output of X, the spanner is Y long, the torque produced is Z. You can increase the force applied the the bolt by getting a longer spanner, increasing Y will give you more Z. This is secondary school physics that i didnt explain very well, but then im a biologist.

Why they are important, well simply if you have more power you will go faster and you will have more torque. If you apply that power differently through gears you can increase the torque.
Why is torque important? The best way to explain this would be you to get on a push bike, put in in top gear and try to pedal from standing.

Answer 4

Well as far as i know and I'm into cars.... Torque is the main output of your engine which is caused by the burst of fuel in the pistons.. things which increases torque include (manifolds, Pistons, exhaust pipe, mufflers (if positioned right), and so on.... when speaking on power usually is horse power. the power which your car gains doing 0-60 and reverse.... the time it takes and the amount of torque u produce..!

I hope it's been a help I'll try to give you sites where you can find more definitive answers..!