An Introduction to Machines: Student Learning Goal The student will be able to identify and describe applications of various types of simple machines (C3.1).

An Introduction to Machines SPH4C 2

Machines A machine is a device that helps us perform tasks. e.g. a machine to trap a mouse

5 Main Functions It may: transform energy (e.g. an electric motor) A motor transforms electrical energy to mechanical energy

5 Main Functions It may: transform energy (e.g. an electric motor) transfer forces (e.g. a car engine) The force on the piston of each cylinder is transferred into the forward motion of the vehicle.

5 Main Functions It may: transform energy (e.g. an electric motor) transfer forces (e.g. a car engine) change the direction of a force (e.g. a pulley)

5 Main Functions It may: transform energy (e.g. an electric motor) transfer forces (e.g. a car engine) change the direction of a force (e.g. a pulley) change the magnitude of a force (e.g. a lever)

5 Main Functions It may: transform energy (e.g. an electric motor) transfer forces (e.g. a car engine) change the direction of a force (e.g. a pulley) change the magnitude of a force (e.g. a lever) change distance or speed (e.g. gears)

Compound Machines Many machines are compound machines, constructed of several simple machines working together.

Simple Machines Simple machines can be split into 2 families: The lever family

Simple Machines Simple machines can be split into 2 families: The lever family The inclined plane family

The Lever Family The lever family consists of the: Lever Pulley Wheel and axle Gears

The Lever Family A lever is a rigid bar that can rotate freely around a support called a fulcrum.

The Lever Family Pulleys, wheels, and gears all rotate completely around a fulcrum.

The Lever Family Pulleys, wheels, and gears all rotate completely around a fulcrum. You can construct systems of pulleys just like you can construct systems of gears.

The Inclined Plane Family The inclined plane family consists of the: Inclined plane Wedge Screw

The Inclined Plane Family An inclined plane is simply a ramp that moves something horizontally as it moves vertically (and stairs may be included).

The Inclined Plane Family A wedge is a double inclined plane.

The Inclined Plane Family A screw is an inclined plane wrapped around a central axis.

Biomechanical Systems Biomechanical systems, which are systems involving a living body, can also be understood as machines, e.g. the human forearm works as a lever.