## Slippery Slide

Click on the arrow in each of the pictures below to see videos of how kids did the project.

## Experiments on a Slide

Lola and Isabella explore sliding. What can they sit on to make them go faster?  Isabella likes combinations of things. First she puts a foam sheet down, places cardboard on top of it, then sits on them both.
• What do you predict will happen?

Predict what materials you can sit on to make you slide fastest: Cotton towel? Wax paper? Aluminum foil? Sand? Wool? Anything else?

• Try sitting on different things to see which is fastest.
• Use the idea of friction to explain your results.

## Experiments on a Cardboard Slope

Lola and Isabella continue to explore sliding with a cardboard slide and a cardboard sled. They attach things to the cardboard sled to make it go better. Both girls included plastic “runners.”  Watch the video with these questions in mind:
• Why do you think Isabella’s sled went down the first time and not at all the third time?
• Why did the plastic spoons and forks work better for Lola than for Isabella?
• Did the wrapping of wax paper help Lola’s sled? Why or why not?

## Things that Don't Help the Cardboard Sled Slide Better

Lola has been experimenting for a while and now summarizes some of the things she has found out.

• Construction paper under the cardboard doesn’t help it slide. But did you see it slide at first? Why do you think that was?
• Aluminum foil doesn’t help it slide.
• A rubber band doesn’t help it slide.

Lola then demonstrates what does work (a plastic fork and spoon under the cardboard sled).  But it doesn’t work!

• Look closely at what happens to the slide and see if you can figure out why the sled that worked in the second video doesn’t work now.

## Why Does the Aluminum Foil Help the Sliding Now?

Lola had found that the aluminum foil under the cardboard sled did not help the sled to go.  Now she will demonstrate this finding.  But the aluminum foil now helps the sled go!  Lola has an explanation:  it is the bumps in the crinkly aluminum foil.

• What do you think of Lola’s explanation?
• Do an experiment to see if crinkly aluminum foil slides better than smooth aluminum foli.
• Can you think of another explanation for Lola’s results?

Look closely at what Lola does to the slope.

• Could raising the end of the cardboard slope make a difference in how something slides down the slope?
• Why?