Target Grade Level:
3
Target Concept:
Change
Target Content Strands:
Communications 
Research 
Universal Themes 
Number Sense 
Numeration, and Operations 
Geometry, Measurement, and Spatial Sense 
Probability and Statistics 
Problem Solving 
Cultural Environment 
Earth, Space, and Physical Environment 
Forces, Matter, and Energy 
Drama Fundamentals 
Visual Arts Performance/Production 
Music Fundamentals 
Music Performance/Production 
Applied Academics 
Personal/Interpersonal Development 
Technical Skills 
Workplace Applications
Suggested Time Line:
Four Weeks
Developed by:
Cheryl Newstead 
Julie Parks 
Marilyn Teat
Year Developed:
1997
 
  Introduction and Overview
 
The purpose of this unit is to provide opportunity to explore simple machines.  Emphasis is placed on the purposes of simple machines.  Students will be able to apply what they learn to their every day life
  
Content Background
 
Gravity
Gravity is a pulling force between one object and another.  The more the matter, the bigger the pull. Some collapsed stars have very strong gravitational pulls.  Their pull is so strong that nothing can escape them, not even light.  Scientists call these stars black holes. Anything that gets too near black hole will be sucked in. 
Force
Force means anything that pushes and pulls.  Everything around you is pushing or pulling, and being pushed and pulled.  Whenever you push on something, it pushes back.  When you increase the distance of movement you use less force.  This is Newton's Third Law of Motion. 
Friction
Friction happens when two surfaces come in contact with each other.  Without frictional book would slip out of your hands no matter how tightly you tried to hold it.  Food would slip off your fork which you would not have been able to hold in the first place. You know that people used to rub two sticks together to start fires.  The fire starts because of the heat caused by the friction. 
Inclined Plane
The inclined plane is a kind of simple machine with slanted surface.  On mountains or steep hills, roads, and walking trails don't go straight up the mountain.  It would be too difficult to walk or drive that way.  Instead, the road winds back and forth up the mountain.  These inclined planes are called switch backs, which are easier to climb. 

The pyramids in Egypt are made of huge stone blocks.  For years people have been wondering how they moved all those heavy blocks around.  The best guess is the Egyptians pushed the blocks up inclined planes in order to build the pyramids. 

Lever
The lever is simple machine made up of a stiff arm or arms that pivots or turns.  The point that a lever turns on is called the fulcrum. The load is the force of the thing you are trying to move.  Over 2000 years ago, a Greek scientist named Archimedes (ark a MEE dees) figured out how and why levers worked.  People had been using levers for a long time, but he was the first to explain them using math.  Legend credits Archimedes with saying, "With a big enough lever, you can move the world." 
Pulley
The pulley is a simple machine made of a rope or chain wrapped around the wheel. A movable pulley reduces the amount of force needed to lift an object by object by increasing the distance over which the force is applied. The useful pulley is one of the earliest and simplest wheel devices.  Back in the eighth century B.C., the country that is now Syria may have discovered that a small wheel within a frame made it easier to pull up a heavy weight hanging from a rope running over the wheel.  Engineers in ancient times used this knowledge to their advantage in the construction of many monuments and temples.
Wheel and Axle
The wheel and axle is a simple machine made of a large wheel attached to a post or axle.  Spanish speaking people arrived in California with their own mining technology.  The arrastre worked much like a wheel and axle.  An upright post was turned by a mule walking on a circular path.  The post, twirling a granite block, ground up rocks that contained gold.
Wedge
The wedge is two inclined planes joined back to back.  Wood has been the main medium for crafts and construction among the Alaskan Natives and American Indians of Northwest Coast region. When building their wooden plank houses, one of the their main tools was the wedge.  Hardwood wedge enable workers to split long planks from tree trunks.  Other wooden products of the American Indians include totem poles, canoes, masks, containers, figurines, tools, and weapons.
Screw
The screw is an inclined plane wrapped around a post. One of the first screw machines was invented by Archimedes in the third century B.C. Archimedes, perhaps the greatest mathematician of his time, designed a machine to lift fresh water from the hold of a ship belonging to King Hiero II of Syracuse. Archimedes' machine had a watertight cylinder enclosing a spiral running from end to end (something like the inside of a mincer), with its lower end immersed in the water. As the machine was turned by hand, the water collected in the rotating spiral blades and was lifted out of the ship's hold.
Additional Background 
The Chinese invented the wheelbarrow almost two thousand years ago.  They called their invention the "wooden ox" or "gliding horse."  A worker could push it or pull it.  Almost 1,300 years passed before Europeans learned of this labor saving device and copied it. 
 
  Student Preparation 
 
Students should have the following skills before the unit begins: 
 

1.  Use of a calculator to multiply and divide. 
2.  Basic understanding of money  
3.  Basic knowledge of a accessing the Internet  
4.  Computer reference skills  
5.  Basic knowledge of money 
6.  Familiarity with how to work in cooperative groups 

 
 This integrated unit was prepared by teachers of the:
 
Henry County Public Schools
396 Tomlinson Street
McDonough, Georgia 30253
USA
Phone:  770/957-6601
 
Questions/Comments 
 Updated 7/28/98