Why it gets easier to push open a door, the further you are from the hinge?
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Simple word: **Leverage**. Base word: **Lever**.
Remember your simple machines from school? The first was **Lever** (then Wheel and axle, Pulley, Inclined plane, Wedge and Screw).
A door is a lever, with the fulcrum being the hinge.
As the lever rotates around the hinge, points farther from this pivot move faster than points closer to the hinge. Therefore, a force applied to a point farther from the pivot must be less than the force located at a point closer in, because power is the product of force and velocity.
Familiar with torque? Torque is measured in ft/lbs (foot pounds). Basically, a measure of a weight at a fixed distance from the pivot.
**20 ft/lbs** is a force equivalent of a 20-pound weight hanging on the end of a wrench 1 foot long. But, if your wrench is TWO feet long (doubled) you only require TEN pounds hanging on the end to equal 20 ft/lbs.
Thus, the longer the wrench, the less weight (effort) it takes to get the same result.
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