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Discover the fascinating world of simple machines, from ancient times to modern applications. Learn about the history, principles, and different types of simple machines that make our everyday tasks easier. Explore the lever, inclined plane, and compound machines, and unlock the secrets of efficient work.
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Simple Machines SPH4C March 2010
History • Archimedes – 3rd Century BC • Heron of Alexandria – 10-75 AD • Galileo Galilei – 1600 AD
What is a machine? • Device that allows us to do work with less effort. • Work is done when a force moves an object in the direction of that force.
Work • Work is the energy transferred to an object. • Machines make work easier. • W is the work done on the object, • F is the magnitude of the force, • Δd is the magnitude of the displacement.
Machines • Machines are designed to achieve at least one of five main functions: • Change energy from one form into another • Transfer forces • Change the direction of a force • Change the magnitude of a force • Change distance or speed
Simple Machine Families • Lever Family • Lever • Pulley • Wheel and axle • Gears • Inclined Plane Family • Inclined plane • Wedge • Screw
Lever A lever is a rigid bar that can rotate freely around a fulcrum ( a support around which a lever can rotate). An effort force, FE, is a force applied to one part of a lever to move a load at another part; the load exerts a load force, FL.
Lever Classes • First-class • Fulcrum between FE and FL • Second-class • FLbetween FEand fulcrum • Third-class • FE between FLand fulcrum
Inclined Planes • An inclined plane is a ramp that increases the load than can be moved by an effort force.
Inclined Planes • A wedge is a double inclined plane that increases the applied or effort force. • A screw is an inclined plane wrapped around a central shaft that increases the applied or effort force.
Compound Machines • A machine made of two or more simple machines.