05+Simple+Machines

__Efficiency__- a measure of how a machine converts input into output. - Efficiency=(input/output)x100 -all machines have efficiencies that are less than 100% __Input/Output__-
 * __Machines__- a device for multiplying forces or simply changing the direction of forces. Conservation of Energy the axiom of all machines, simple or complex.

__ Six Simple Machines: __**

**__Lever-__ a rigid object that is used with an appropriate fulcrum or pivot point. The mechanical advantage is to multiply the mechanical force that can be applied to another object. Most commonly seen on a playground.**




 * __Wheel and Axle__- is a lever in which the radius of the wheel is the effort arm and the radius of the axle represents the resistance arm. Most commonly seen above a well. **

  ** __Wedge__- A portible inclined plane that can seperate two objects. The mechanical advantage of a wedge depends on the ratio of its length to its thickness. Where a short wedge with a wide angle does the job faster, it requires more force than a long wedge with a smaller angle. Most commonly seen in an axe. **

**__Pulley__- a wheel with a groove going around the circumference through which runs a rope, when one side of the rope is pulled the object connected to the other side rises of the ground. It is used to change the direction of an applied, transmit rotational motion, or realize a mechanical advantage in either a linear or rotational system of motion.**


 * __Inclined Plane__- is a flat surface whose endpoints are at different heights. By moving an object up an inclined plane rather than completely vertically, the amount of force required is reduced, at the expense of increasing the distance the object must travel.The mechanical advantage of an inclined plane is the ratio of the length of the sloped surface to the height it spans. Most commonly seen in ramps.**


 * __Screw__- a shaft with a spinning groove and provisions at one end to turn the screw. It translates torque into linear force. Can also be described as an inclined plane wrapped around a shaft. Most commonly seen in a screw. **