AS THE WHEEL TURNS
Grades 4 - 8

During prehistoric times, people did not have wheels and pulleys as we know them today. The earliest wheels date back to about 3500 B.C. They were fastened solidly to their axles so wheel and axle moved together. However, over the course of time, innovative thinking transformed the wheel into a very useful machine - from the basic cart and chariot to door knobs, pencil sharpeners and steering wheels. The wheel has helped change the course of history. This lesson is an introduction to the concept of simple machines and how they are used to make work easier. It covers wheels and axles and the pulley. The video segments of this lesson explain ho wheels and pulleys work and their direct relationship to distance and force. The viewing and post-viewing activities will bring the ideas from the video segments into concrete, hands-on explorations of the everyday world of simple machines. This lesson will take approximately 3 40-minute class periods.

Eureka! - "Unit 2: Simple Machines, Programs 14-15"
Bill Nye, The Science Guy - "Simple Machines"

Students will be able to:

• define the term wheel and axle;
• define pulley;
• define single-fixed pulley;
• define moveable pulley.

Per class:

• toys that use pulleys or wheels such as model sailboat, steam shovel, trolley
• car, Hook & Ladder truck, a yo-yo or skateboard
• different types of pulleys
• clothesline
• rope
• child's bicycle
• exercise equipment
• small wheels

Per group of three or four students:

• old magazines
• three pencils
• 4-foot (approximately 1m 6cm) long board
• flat, heavy rock or brick (small enough for a rubber band to fit around)
• junk mail
• 6-inch (20 cm) piece of heavy string
• spool
• screw hook
• construction paper
• glue
• heavy rubber band
• several yards (meters) of heavy string
• heavy book
• tagboard

• axle - a rod on or with which a wheel revolves
• wheel- a solid disk, or a circular frame connected by spokes to a central hub, capable of turning on a central axis and used to move vehicles or transmit power in machinery
• fulcrum - the point of support on which a lever turns in raising or moving something
• pulley - w heel with a groove between its edges that holds a wire or rope
• single-fixed pulley - one pulley attached to an object
• single-moveable pulley - one pulley that is attached to a wire or rope in such a manner as to be able to move with the wire or rope
• gear - a system of two or more toothed wheels meshed together so that the motion of one is passed on to the others

Bring in several toys that have wheels or pulleys. Some students may have some from home. Have students identify the parts of the toys that help them to move or perform some other task. See if they can identify pulleys. Ask them how they think simple machines cause movement.

Set up a pulley and line across the classroom. Discuss with students places they may have seen something like this used (e.g. clothesline, sailboats, movies companies lifting furniture, etc.)

Have students design a bookbag that will move effortlessly on wheels. They can use a skateboard in their design.

Have students make a list of machines that use wheels and pulleys that they have seen in their homes.

Create an invention time line.

Bring in a child's bicycle and have students try to identify not only the wheels, but the gears and the pulleys and what their purpose might be.

Bring in simple exercise equipment that uses wheels or pulleys to make work harder in order to stretch specific muscles.

Review with students a lever and how it works.

First Segment

To give students a specific task and engage their viewing attention, hand out the attached sheet labeled "Focus for Viewing 1" and tell students that they must answer the questions as they are watching the following segment.

Second Segment

To give the students a specific task an engage their viewing attention, hand out the attached sheet entitled, "Focus for Viewing 2," and tell students that they must answer the questions on the sheets as they are watching the following segment.

Third Segment

To give the student a specific task and engage their viewing attention, hand out the attach sheet labeled "Focus for Viewing 3" and have students answer questions as they watch the next segment.

Fourth Segment

To give the student a specific task and engage their viewing attention, hand out the attached sheet labeled "Focus for Viewing 4," and tell students that they must answer the questions as they watch the segment.

First Segment

Set the memory unction of your remote/VCR, or set the counter to 000 at the beginning of "Eureka!", episode 14, entitled "The Screw and the Wheel." FAST FORWARD to the beginning of episode 15, "The Pulley." PLAY the review section of the video entitled "The Story So Far," PAUSING after each of the groups of words to discuss vocabulary and concepts (see attached handout labeled "The Story So Far"). Press MEMORY FUNCTION and wait for tape to complete its cycle. FAST FORWARD to where the phrase "The Screw" is on the screen. Push PLAY and continue to end of segment. STOP; eject the tape and insert the "Bill Nye, the Science Guy" program.

Second Segment

FAST FORWARD to the first section of the Bill Nye tape called "Consider the
Following" and PLAY. Push PAUSE when you see Bill Nye coming down the fire pole. Take a few minutes to allow students to jot down the answers for the handout. Eject the tape and insert he "Eureka!"program.

Third Segment

FAST FORWARD to the beginning of "Eureka!" episode 15. STOP where you see "600 N" on the pulley ropes and you hear the words, "This piece of rope supporting 600 N." EJECT the tape and insert the "Bill Nye" program.

Fourth Segment

FAST FORWARD the Bill Nye program until you see the words "Way Cool Scientist" on screen. PLAY. STOP when the words "Tour de Science 93" appear on screen. FAST FORWARD to "Hey, look at this!"; PLAY to the end. STOP tape.

Discuss the concept of force and distance when used to describe simple machines. Show students that with a simple machine force is reduced but the distance over which the force must be applied increases. This is an inverse relationship. As one variable increases, the other decreases. Explain the phrase used int he Bill Nye video, "Long is lazy and Short is serious sweating."

Have students build and experiment using a pulley. Screw a hook into a 4-foot long board. Hang a spool from the hook using heavy string. Attach the book tot he string. Thread the extra string around the spool. Place the board across the backs of two chairs and pull on the string to life the book.

What happens when students pull the string?

How does the pulley help to decrease the force?

Have the students think of other ways pulleys could be used to make work easier.

Direct students to build and experiment using a simple wheel design. Place a rubber Band around the flat heavy rock. Put one end of a 6-inch piece of heavy string through the rubber band and make a loop large enough for a finger to fit through. Have a student put the rock on the floor and try to pull the rock toward the with their finger. Is it easy to pull?

Place three pencils under the rock. Direct students to put their finger through loop and pull the rock again. Is the rock easier or harder to move this time? Why is one way of pulling the rock easier than the other?

Have students design different shapes of propellers using tag board or plastic. They could make pinwheels or small boats to test their designs. Which designs work best? Which ones work the fastest? Hold a contest for the fastest, biggest, most original, etc. propeller.

• Direct students to use the Internet or World Wide Web to investigate history and uses of wheels and pulleys. The students could also contact engineers this way and ask them about how these simple machines are used when they design things.
  
  
• Direct students to write for information on Patents.
  
  
• Visit a hands-on museum and look for examples of wheels and pulleys.
  
  
• Have a mechanical engineer talk to the class.
  
  
• Contact the Chamber of Commerce for information on community industry.

SOCIAL STUDIES:
Make a time line of the Industrial Revolution.

Direct students to research great inventors such as Jonas Salk, Thomas Edison, Johann Gutenberg, etc.

Direct students to research great inventions such as the cotton gin, typewriter, elevator, etc. that use wheels and pulleys in their design.

LANGUAGE ARTS:
Write stories about the pros and cons of progress.

ART:
Make collages of simple machines or life around the time of the Industrial Revolution.

MUSIC:
Replay the end rap song section of the Bill Nye video using audio only and have students sing. They could also think up dance steps and perform for parents or other students as a "Simple Machine." Program as the end of the unit on simple machines.

Master Teachers: Virginia Trombley and Raymond Dubuque
Mountain Lake Public Broadcasting/Plattsburgh, NY