Learn how Levers Work in this educational video from dizzo95.
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Male Speaker: In order to get leverage, a lever must have a fulcrum. How much leverage can be gained depends on the length of the lever, where the fulcrum is placed, where force or effort is applied and finally were the load is positioned, there are three basic arrangements that will yield different kinds of leverage. In one case the force and the load are on opposite sides of the fulcrum. When the applied force and the load are at equal distances from the fulcrum the force applied will equal the force to the load, no leverage advantages gained but if the fulcrum is moved so that were the force is applied is twice the distance from the fulcrum than the load, only half the upper will be needed to move the load leverage will increase proportionally by shifting the fulcrum closer to the load. This proportion is called mechanical advantage. An example of this lever arrangement is the gripping capacity of a pair of pliers and the powerful leverage of a ply bar. In another case the load lies between the fulcrum and the point of effort the closer the load is to the fulcrum the greater the mechanical advantage, again the same rules are proportion at work if the effort applied is three times farther from the fulcrum than the load the amount of effort needed to move the load is reduced to a third. This lever form is found in a wheel barrow and a nut cracker. In the third case the force is applied between the load and the fulcrum very different from the first two cases this type of lever does not multiply force but instead multiplies motion the load experiences less force than the effort but moves it proportionally greater distance as with the fishing rod pulling a fish or a pair of tweezers grasping an object for all these levers what is gained in motion is lost in force. The larger force always moves through the small.

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