WHAT IS A MACHINE? Machine: A device that makes work easier by changing the size or direction of a force When you think of a machine, you may think of things such as cars, big construction equipment, or even computers, but not all machines are complicated…..
SIMPLE MACHINES
WORK INPUT & OUTPUT Work Input: The work being done on a machine Work Output: The work being done by a machine **In the pictured example, the screwdriver is the machine
MECHANICAL ADVANTAGE Mechanical Advantage is the number of times a machine multiplies force. In other words, it compares the input force with the output force.
MECHANICAL ADVANTAGE A machine has mechanical advantage if the output force is greater than the input force
TYPES OF SIMPLE MACHINES 1) Lever 2) Pulley 3) Wheel and Axle 4) Inclined Plane 5) Wedge 6) Screw
LEVER Lever: A simple machine that consists of a bar that pivots at a fixed point called a fulcrum Example: Have you ever seen a nail get removed from a piece of wood with a hammer? If so, the hammer was being used as a lever
PULLEY Pulley: A simple machine that has a grooved wheel that holds a rope or cable
WHEEL AND AXLE Wheel and Axle: A simple machine consisting of two circular objects of different sizes; the wheel is the larger of the two circular objects
INCLINED PLANE Inclined Plane: A simple machine that is a straight, slanted surface, which facilitates the raising of loads. Example: A ramp is an example of an inclined plane
WEDGE Wedge: A simple machine that is made up of two inclined planes and that moves Example: Some very commonly used wedges are knives and doorstops
SCREW Screw: A simple machine that consists of an inclined plane wrapped around a cylinder Used most commonly as fasteners
COMPOUND MACHINES Compound Machine: A machine made of more than one simple machine