LESSON 1: WORK, ENERGY AND POWER
 WORK: THE USE OF FORCE TO MOVE AN OBJECT
 BOTH FORCE & MOTION MUST BE IN THE SAME DIRECTION
 EQUATION: WORK = FORCE x DISTANCE
 UNITS OF WORK : 1 NEWTON * 1 METER = 1 JOULE (1 Nm)
 ENERGY: THE ABILITY TO DO WORK
 ENERGY IS NECESSARY TO DO WORK
 UNITS OF ENERGY – SAME AS UNIT OF WORK : JOULES (j)
 WORK TRANSFERS ENERGY TO AN OBJECT
 POWER: HOW FAST WORK IS DONE
 EQUATION: ENERGY ÷ TIME
 UNITS OF POWER: JOULE PER SECOND (JOULE/SEC) = 1 WATT
•
NAMED AFTER JAMES WATT (STEAM ENGINES, 1800’S)
•
1 HORSEPOWER = 746 WATTS
LESSON 2: KINETIC AND POTENTIAL ENERGY

KINETIC ENERGY (KE): THE ENERGY OF MOTION (measured in joules)
 ALL MOVING OBJECTS OR MOLECULES HAVE KINETIC ENERGY
 KINETIC ENERGY DEPENDS ON MASS AND SPEED
 EQUATION: ½ mv3
 POTENTIAL ENERGY (PE): STORED ENERGY (measured in joules)
 POTENTIAL ENERGY HAS THE ABILITY TO DO WORK
 TYPES OF POTENTIAL ENERGY
 GRAVITATION POTENTIAL ENERGY BASED ON HEIGHT
 GPE = mass x 9.8 m/s2 x height (gpe = m*g*h)
 GREATER HEIGHTS RESULT IN GREATER gpe.
 ELASTIC POTENTIAL ENERGY STORED IN STRETCHED OBJECT
 MECHANICAL POTENTIAL (ME) STORED IN POSITION
 NOT HEIGHT ABOVE GROUND (gpe)
 EQUATION: ME = KE + PE
3
 CHEMICAL POTENTIAL STORE IN BONDS BETWEEN ATOMS
 MACHINES: DEVICES THAT MAKE WORK EASIER
 MACHINES CAN CHANGE SIZE OF FORCE, DIRECTION OF FORCE, & DISTANCE OF FORCE
 SIMPLE MACHINES MAKE UP MACHINES
 SIMPLE MACHINES MAKE WORK EASIER WITH A SIMPLE MOTION
 6 SIMPLE MACHINES: RAMPS, LEVERS. WHEELS/AXLES, SCREW, WEDGES, PULLEYS
 MACHINES CAN MULTIPLE FORCE OR MULTIPLE DISTANCE
 CANNOT DO BOTH AT THE SAME TIME
 FORCE MULTIPLIED FORCE AT THE COST OF LONGER DISTANCES
 DISTANCE MULTIPLIED AT THE COST OF GREATER FORCES
 CAN NEVER MULTIPLY WORK
 MECHANICAL ADVANTAGE: INDICATES HOW FORCE (OR DISTANCE) IS
MULTIPLIED
 MA = 1: DISTANCE MULTIPLIED
 MA > 1 FORCE MULTIPLIED
 MA < 1 DISTANCE MULTIPLIED
 MA EQUATION: MA = OUTPUT FORCE ÷ INPUT FORCE
 OUTPUT FORCE: FORCE DONE BY THE MACHINE
 INPUT FORCE: FORCE YOU PUT INTO MACHINE
 MECHANICAL EFFICIENCY: INDICATES HOW MUCH WORK IS LOST TO FRICTION
 ME IS ALWAYS A PERCENTAGE LESS THAN 100% (FRICTION ALWAYS PRESENT)
 ME EQUATION: ME = (WORK OUTPUT ÷ WORK INPUT ) x 100
 WORK OUTPUT: WORK DONE BY THE MACHINE
 WORK INPUT: WORK YOU PUT INTO A MACHINE
THE 6 TYPES OF SIMPLE MACHINES
1. LEVER: A BAR THAT PIVOTS ON A FULCRUM (THE PIVOT POINT OF A LEVER)
1ST CLASS LEVER: FULCRUM IN MIDDLE (“F”)
MULTIPLES FORCE OR DIRECTION AND CHANGES DIRECTION
EXAMPLE: SEE-SAW
2ND CLASS LEVER: RESISTANCE (OBJECT) IN THE MIDDLE (“R”)
MULTIPLES FORCE WITHOUT CHANGING DIRECTION
EXAMPLE : WHEEL BARROW, RAKES
3RD CLASS LEVER: EFFORT IN THE MIDDLE – YOU – (“E”)
MULTIPLIES DISTANCE WITHOUT CHANGING DIRECTION
USED TO MULTIPLE THE MOMENTUM TRANSFERRED TO OBJECTS IN SPORTS
EXAMPLES: BASEBALL BATS, GOLF CLUBS, HAMMERS
 3. WHEEL AND AXLE: A LARGER WHEEL THAT TURNS A SMALLER SHAFT
 MA OF A WHEEL & AXLE THE RESULT OF THE THEIR SIZE DIFFERENCE
 MA = RADIUS OF INPUT (WHEEL) ÷ RADIUS OF OUTPUT (SHAFT)
 LARGER WHEELS CREATE GREATER MA
 4. INCLINED PLANES: A SLANTED, FLAT SURFACE ( A RAMP )
 LONGER RAMPS HAVE A GREATER IDEAL MA
 LESS FORCE BUT LONGER DISTANCES
 FRICTION REDUCES THE ACTUAL MA OF RAMPS
 IDEAL MA OF A RAMP = RAMP LENGTH ÷ RAMP HEIGHT
5. WEDGES: A MOVABLE SINGLE OR DOUBLE INCLINED PLANE
LONGER, THINNER WEDGES HAVE GREATER IDEAL MA
EXAMPLES: HAMMER CLAW, CHISEL, KNIFE EDGE
6. SCREW: AN INCLINED PLANE WRAPPED AROUND A CYLINDER
THREADS: THE TERM FOR THE RIDGES ON A SCREW
CLOSER THREADS HAVE GREATER IDEAL MA
 3. PULLEYS: A GROOVED WHEEL AND AXLE HOLDING A LINE OR ROPE
 IDEAL MA OF A PULLEY SYSTEM EQUALS THE # OF LINES HOLDING UP OBJECT
 FIXED PULLEYS: ATTACHED TO A STATIONARY OBJECT: CANNOT MOVE
 CAN ONLY CHANGE THE DIRECTION OF FORCE
 ALWAYS HAVE AN IDEAL MA OF 1
 MOVABLE PULLEY: NOT ATTACHED, FREE TO MOVE UP AND DOWN
 MOVING PULLEYS DO NOT CHANGE THE DIRECT OF FORCE
 MOVING PULLEYS MULTIPLY FORCE AT THE COST OF LONGER DISTANCES
 PULLEY SYSTEMS (BLOCK AND TACKLES) COMBINE FIXED AND MOVING PULLEYS
 PULLEY SYSTEMS MAY BOTH CHANGE DIRECT OF FORCE AND MULTIPLY FORCE
 PULLEY SYSTEMS MULT. FORCE: MA = # OF LINES HOLDING MOVABLE PULLEY
COMPOUND MACHINES: A COMBINATION OF SIMPLE MACHINES
 TOTAL IDEAL MA : PRODUCT OF ALL SIMPLE MACHINES. WHICH MAKE IT UP
 GEAR SYSTEM: AN EXAMPLE OF A COMPOUND MACHINE
SIMPLE MACHINES IN THE HUMAN BODY
 FOREARM: EXAMPLE OF 3RD CLASS LEVER
 BALL OF FOOT: A 2ND CLASS LEVER
 NECK: A FIRST CLASS LEVER
 INCISORS: TEETH WHICH FUNCTION AS WEDGES
ROSIE, http://users3.ev1.net/~de238/stewart/stewartgraphics/r_riviter.gif
IRON WORKERS, http://whyfiles.org/170skyscraper/images/iron_workers.jpg
WELDER, http://www.aoe-coe.com/gif/welder.jpg
MIGRANT WORKERS, http://www.saludparalagente.org/graphics/migrant_workers.jpg
SINGER MACHINE, http://www.antiqbuyer.com/images/sewing%20machine/sing20a.jpg
SIMPLE MACHINES, http://www.sirinet.net/~jgjohnso/sixsimplemach.jpg
BIKE, http://http://www.jek2004.com/Simple-machines-cover-sketc.jpg
INPUT/OUTPUT, http://discover.edventures.com/images/termlib/m/mechanical_advantage/support.gif
Effort/load, http://www.dtonline.org/areas/6/1/2/p.gif
See/saw, http://library.thinkquest.org/CR0210120/Media/see%20saw
Pulley, http://www.sciencetech.technomuses.ca/english/schoolzone/images/fPulley2.GIF
SIMPLE MACHINES, http://myschoolonline.com/image/display/local/0,2306,MA-31670,00.gif
INCLINED PLANE: http://www.skooltools.com/Agri-Science/Ag%20Mechanics/Images/Inclined%20Plane%20Poster.jpg
SCREW:http://discover.edventures.com/images/termlib/s/screw/support.gif
LEVER: http://discover.edventures.com/images/termlib/l/lever/support.gif
PULLEY: http://discover.edventures.com/images/termlib/f/fixed_pulley/support.gif
WHEEL: http://discover.edventures.com/images/termlib/w/wheel/support.gif
ROTATE LEVER: http://discover.edventures.com/images/termlib/r/rotary_to_lever_motion/support.gif
LEVERS: http://discover.edventures.com/images/termlib/t/third_class_lever/support.gif
WEDGE: http://discover.edventures.com/images/termlib/w/wedge/support.gif
SCREWS: http://www.yourdictionary.com/images/ahd/jpg/A4screw.jpg
TRUCK RAMP: http://www.equipmentandsupply.com/yardramp.jpg
SCREWS: http://www.mertons.com/img_content/bronze-screws-2.jpg
SISSORS: http://gsn.k12.oh.us/PaintValley/web_page_contest/Final%20Pictures/sissors.jpg
http://img.ebigchina.com/cdimg/172748/655213/0/1098606459.jpg
http://www.thecei.org.uk/BikeStreet/old-bike.jpg
http://www.phys.unsw.edu.au/~jw/graphics/blocks1.GIF
http://db.library.queensu.ca/steam/wever/gcldc%20pulleys/Ki%20marina%20pulleys.jpg
http://physics.ucsc.edu/~josh/6A/book/forces/img60.gif
www.istockphoto.com/file_thumbview_approve/438808/2/istockphoto_438808_wagon_wheel_and_axle
http://home.earthlink.net/~ocleide/HW_portrait.jpg
http://www.thecei.org.uk/BikeStreet/old-bike.jpg
http://muaythaitraining.files.wordpress.com/2007/06/anatomy-of-the-elbow.gif
http://www.dental.ufl.edu:1180/Offices/Operative/Faculty_pages/Gordan/images
http://www.openerg.com/psz/images/feet.gif
http://www.toyourhealth.org.uk/content/image/incisor.gif
http://www.tpub.com/content/engine/14037/img/14037_43_2.jpg
http://www.unis.org/UNIScienceNet/Bicycle_1.jpg
http://upload.wikimedia.org/wikipedia/commons/thumb/b/b7/Pulleys.svg