1. Work and Machines Simple Machines

2. Work and Machines Machines make work easier to do –They change the size of a force needed, the direction of a force, or the distance over which a force acts

3. Work and Machines Work Input and Work Output –Because of friction, the work done by a machine is always less than the work done on the machine

4. Work and Machines Work Input to a Machine –Input force- the force you exert on a machine –Work input- the work done by the input force acting through the input distance

5. Work and Machines Work Output of a Machine –Output force- the force that is exerted by a machine –Output distance- the distance the output force is exerted through –Work output- the output force multiplied by the output distance

6. Simple Machines Six types of simple machines: –Lever –Wheel and Axle –Inclined Plane –Wedge –Screw –Pulley

7. Simple Machines Lever- a rigid bar that is free to move around a fixed point –Fulcrum- the fixed point the bar rotates around http://visual.merriam-webster.com/science/physics- mechanics/lever.php#bar32386

8. Simple Machines Wheel and Axle- consists of two disks or cylinders, each one with a different radius http://en.wikipedia.org/wiki/Wheel_and _axle

9. Simple Machines Inclined Plane- a slanted surface along which a force moves an object to a different elevation http://homeschooling.about.com/od/freeprintables/ss/machinecolor.htm http://www.springboardm agazine.com/science/sim plemachines.htm

10. Simple Machines Wedge- a v-shaped object whose sides are two inclined planes sloped toward each other http://www.sciencephoto.com/media/83826/enlarge http://www.newagearbor.com.au/shop/prod334.htm

11. Simple Machines Screw- an inclined plane wrapped around a cylinder http://en.wikipedia.org/wiki/File:GearBoxRotLinScrew.gif#filelinks http://en.wikipedia.org/wiki/Screw_(simple_ma chine) http://www.b2bscrews.com/furniture- screw.htm

12. Simple Machines Pulley- consists of a rope that fits into a groove in a wheel http://www.sparknotes.com/testprep/books/sat2/physics/chapt er8section2.rhtml http://science.howstuffworks.com/transport/engines- equipment/pulley.htm

13. Simple Machines Compound Machine- any combination of two or more simple machines