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  TechnologyMechanical Engineering and Machinery
a lever, one of the basic machines Machines in General

ma shEn', (1) an apparatus consisting of interrelated parts with separate functions, used in the performance of some kind of work; (2) a device that transmits or modifies force or motion


CONTENTS
Kinetic vs Potential EnergyKinetic vs Potential Energy A child on a playground swing illustrates the difference between potential and kinetic energy.
The Law of the Conservation of EnergyThe Law of the Conservation of Energy Energy can be changed in form, but cannot be created or destroyed; this is the basic law of the conservation of energy.
How Machines Change the Directions of MotionHow Machines Change the Directions of Motion Changing linear motion to rotary motion requires some kind of piston, a connecting rod, a crankshaft, and a flywheel. Changing rotary motion to linear motion involves the use of a wheel, drive pin, and slotted yoke.
The LeverThe Lever consists of a rod or plank that is free at both ends, and some steady object on which the plank can rest. The braced, or fixed, part is called the fulcrum. The distance from the load to the fulcrum is the load arm. The distance between the fulcrum and the lifting force is the effort arm.
The Inclined PlaneThe Inclined Plane The secret of the inclined plane's mechanical advantage: for an object resting on the plane, the vertical force of gravity acting on it is split into two smaller forces, one perpendicular to, one parallel to the plane.
The ScrewThe Screw can be imagined as a cylinder with an inclined plane wrapped around it. A screw finds its mechanical advantage in the ratio of two dimensions: the length of the lever that turns it and the distance between threads (pitch).
The WedgeThe Wedge is essentially a double inclined plane. It differs from the inclined plane, however, in that it is intended to be pushed under or into the load instead of having the load pushed or pulled up along the plane.
The Wheel and AxleThe Wheel and Axle is a first-class lever. The center of the axle corresponds to the fulcrum. The radius of the axle corresponds to the load arm. The radius of the wheel corresponds to the force, or effort, arm to which force is applied. Sometimes a crank is used instead of a wheel.
The PulleyThe Pulley is a wheel over which a rope or belt is passed for the purpose of transmitting energy and doing work. The simplest pulley is a grooved wheel on a fixed axle. A rope passed over this wheel is tied to the load to be lifted, and a pull is applied to the other end of the rope.
Miniature Gears and Ball BearingsMiniature Gears and Ball Bearings
Tape-Directed MachinesTape-Directed Machines
Automatically Controlled MachineAutomatically Controlled Machine
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This page was last updated on 03/23/2016.

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