# PRINT ARTICLE

VARIOUS NOTES: SIMPLE MACHINES

Chapter 4 summary

WORK- force acting over a distance to move an object

JOULE- unit of work and energy

POWER- rate at which work is done
WATT- unit of power (1 joule per second)
MACHINE- device that makes work easier by changing distance or direction of the force
WORK INPUT- work that goes in a machine and is exerted over a distance
WORK OUTPUT- work that comes out of the machine and is exerted over a distance
EFFICIENCY- comparing work input to the work output
MECHANICAL ADVANTAGE- number of times a machine multiple the effort force
IDEAL MECHANICAL ADVANTAGE- The more efficient a machine is, the closer it is to this
EFFORT- force exerted on a machine
FORCE- push or pull
FRICTION- acts on an object to make it slow down or stop
PITCH- distance between the threads of a screw
RESISTANCE- force to be over come by a machine

1. INCLINED PLANE: flat surface that is higher at one end and it multiples force
2. WEDGE: inclined plane that moves (example &ndash; ax)
3. SCREW: inclined plane that is wrapped around a pole or cylinder to form a spiral
4. LEVER: bar to freely move around a single point
5. PULLEY: rope, belt or chain wrapped around a wheel, change amount or direction of force
6. WHEEL AND AXLE: a larger circle and a small circle placed next to each other to work together
7. COMBINATION MACHINE: two or more simple machines that are working together

Formulas:
Work=force x distance
Work is measured in joules or newton/meters
Force is measured in newtons

***KNOW THAT A MACHINE ONLY DECREASES THE AMOUNT OF WORK THAT YOU DO, NOT THE TOTAL AMOUNT OF WORK DONE. THAT REMAINS THE SAME!!!

***KNOW THAT an inclined plane wrapped around a cylinder is called a SCREW

***KNOW THAT in a screwdriver, the handle is the wheel and the shaft is the axle. It is actually a wheel and axle!!!

***KNOW THAT in order to do WORK, an object MUST BE MOVED as a result of force!!!

Distance is measured in meters

POWER = WORK/TIME
Power is measured in WATTS
WORK IS MEASURED IN JOULES
TIME IS MEASURED IN SECONDS