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 beingdone 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