AFSL

• 2 feet of string
• 1 plastic cup
• 1 wooden block with a hook attached
• 1 hole puncher
• 1 friction board

• Punch two holes in the top of the cup and attach the string to the cup.
• Attach the other end of the string to the wooden block.

Explain:

·  Friction is the force that slows things down.  When two objects push or rub against each other, they cause friction.

·  Different materials create different amounts of friction. Some materials are easy to move across and some materials are more difficult to move across.

·  Describe materials on the friction board:  cardboard, cork, rubber and sand paper.

·  Allow students to feel the materials.

·  Demonstrate: Measuring friction

1. Tape or secure the friction board to a table with the edge lined up to the table edge
2. Place the block of wood at the far edge of one of the materials on the friction board.
3. Allow the string and cup to hang straight off the edge of the table.
4. Students carefully place Unifix cubes, pennies or beans into the cup until the block moves across the selected material.
5. Record the number of counters needed to move the wood block across the material.
6. Repeat experiment procedure with each material on the friction board.

Student participation:

1. Students predict which material will have the most and least friction.
2. Students place the block on each material and add counters to the cup until the block moves across the material.
3. Students observe and/or record the number of counters needed to move the block across each material.
4. Discuss essential questions:
   1. Which material had the most friction and needed the most counters to move the block?
   2. Which material had the least friction and needed the least number of counters to move the block?