Sliding Along

L'Ouverture Perkins Carter Elementary School
5740 S. Michigan Ave.
Chicago IL 60647
(312) 535-0860

OBJECTIVES:

Compare and contrast movement of objects on smooth and rough surfaces. Third grade level State Goal #1 - The concepts and basic vocabulary of biological, physical
and environmental sciences and their application to life
and work in contemporary technological society.

General knowledge /skill related to State Goal #1
How two or more things interact and the effect each has on the other.

Third grade objective Demonstrate the relationship of complex machines and friction. MATERIALS NEEDED:

1 wooden board 3 feet by 2 feet (approx)
1 metal tray or board
1 matchbox
1 piece of stone
1 piece of wood
1 eraser
1 ice cube
2 bowl
1 rubber ball
1 tennis ball
1 jar
soap and water
real money
2 pieces of sandpaper
vaseline or margarine
oil and grease
bicycle tire
car tire
1 small flat bottle

STRATEGY:

anticipatory set To begin this lesson on the exploration of friction you can introduce this little "science trick": 1. Take out some money and put it inside of a jar. 2. Screw on the lid of the jar as hard as you can. 3. Choose a student and wash their hands thoroughly with soap and water 4. Do not dry their hands; keep them soapy. 5. Challenge the student to get the money out of the jar. *6. Student should not be able to open the jar if hands are slippery. Experiment #1 Investigate Friction Materials - Wooden board, matchbox, piece of wood, eraser and an ice cube

1. Arrange the objects in a line along the edge of the wooden board.
2. Slowly raise the board until the objects begin to move.
3. Which object moved first?
4. Repeat the experiment using the metal tray.
5. Do the objects move more easily.....or less easily?
6. Do you have to to lift the metal tray higher than the wooden board before
the objects will move?
7. Which surface has the lowest friction?


Experiment #2 Friction in Water Materials - bowl, water, tennis ball and rubber ball

1. Get a smooth rubber ball and a tennis ball.
2. Put a little water in the bowl.
3. Spin each ball in the bowl.
4. Which one moves more easily?


Experiment #3

Reducing Friction with Water

Materials - metal tray, soapy water, flat small bottle, books for incline

1. Prop up the tray on the books to make a slope.
2. Wet one side of the tray and try sliding the bottle down each side in turn.
3. Now rub soap on the wet side and slide the bottle down again.
4. On which surface does the bottle slide most easily?

Performance Assessment#1

Materials - Two pieces of sandpaper, oil and/or grease

1. Student will take two pieces of sandpaper.
2. Student will rub the two pieces of sandpaper
3. Student will be asked to reduce the friction of the two pieces of sandpaper.

Student should realize that using grease or oil between the two pieces of
sandpaper will reduce the friction.

Performance Assessment #2

Materials - matchbox, stone, wood, eraser, ice cube, wooden slide, metal
slide, soapy wet slide, 1. Student will choose object and slide that have the least amount of friction between the two surfaces from larger choice of objects and different slides. 2. Student will choose object and slide that have the greatest amount of friction between the two surfaces from larger choice of objects and different slides. 3. Student will time both experiments and determine the range of difference. Reference - 175 Science Experiments, Brenda Walpole, Random House; 1988

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