## Frictionally Speaking

### Dawn Pack

#### Description

All you need to teach your students about the effects of friction on a moving object is a handful of marbles, a paper cup, and string.

#### Objectives

The student understands how friction affects an object in motion.

#### Materials

-Paper cups (6 to 8 ounce) Purchase enough of the cups so that each goup of students has one cup.
-String, approximately one skein. Purchase enough string so that each group of students has 18 inches of string .
-Marbles. Purchase enough marbles so that each group of students can have 15 marbles.
-Sandpaper, fabric, construction paper, and other surfaces. Gather enough different surfaces so that each group of students can have an 8x8 inch piece of each surface.
-Scissors
-Ruler

#### Preparations

1. Poke two holes near the bottom of each paper cup (One hole should be 3/4 of an inch from the bottom of the cup. The other hole should be 1/2 inch directly above the first hole.)See attached file "Cup and String Diagram".
2. Cut one piece of string per cup. The string should be 18 inches long.
3. Loop the string through the two holes you made in the cup and tie the ends so that they will not come loose. (students will need to hold the string up at a 45 degree angle from the cup)
4. Prepare sets of fifteen marbles for each group.
5. Cut the various materials into 8x8 squares (these measurements need not be exact).
6. If there are surfaces of the same color, label them 'surface 1', 'surface 2', etc. or 'surface A', 'surface B', etc.
7. Make copies of the lab sheet for each group of students. See attached file "Frictionally Speaking Lab Sheet".
7. Draw the lab sheet on the board (this will be filled in at the end of the activity).

#### Procedures

Note: This activity is intended as an introduction to the concept of friction.

1. Tell the students they are going to investigate a force found in nature. Give the students the definition of friction and ask where they have witnessed friction at work in their lives (ie: tires on the road, skateboard on the sidewald, slipping on a wet floor, etc.). If they keep a vocabulary notebook, you may want to have them add the definition of friction.

2. Divide the students into small groups of two or three.

3. Give each group one cup with string attached and fifteen marbles. Instruct them to place the marbles in their cups.

4. Show the students how to hold the string at a 45 degree angle and pull the cup toward themselves. Let them practice this process several times by pulling the cup across their desk. They are ready to begin the activity when they can successfully pull the cup without spilling the marbles.

5. Distribute the surfaces and lab sheets(one per group) to each group of students. Describe each surface so the students are familiar with their qualities and how these qualities might affect friction. You may want to fill out the surface column of the lab sheet now or allow students to do this as they test each one.

6. Student partners should hold the back corners of the surface to keep it in place while the other partner slides the cup. Students should switch positions so that each partner slides the cup over each surface. Partners should discuss the results then record them on the lab sheets.

7. Repeat the process with each surface so the students can determine the differences in the friction of each different type of surface.

8. Discuss the activity after all surfaces have been tested. Fill in the board lab sheet as students share their observations.

#### Assessments

Students will be formatively assessed by showing an understanding of how friction affects an object in motion. Each partner-group will test various surfaces and write their observations on their lab sheets.

#### Extensions

1. This activity may be used as a center, if desired.

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#### Attached Files

Friction Definition     File Extension: pdf

Cup and String Diagram     File Extension: pdf

Frictionally Speaking Lab Sheet     File Extension: pdf