Source: Scholastic's The Magic School Bus Science Explorations A


Rub a Dub

Things rubbing together cause a force called friction.
Some things have more friction than others. Try rubbing your hands together. Can you feel the friction? Now put some lotion on your hands and try again. Can you feel the difference? There is still friction, but not as much.

Why does a rolling marble stop?
Friction makes a rolling marble slow down and stop. What things cause more friction? Find out with a marble launcher.

Set up a marble launcher like the one in the picture. Put it on a bare floor.

2. Put a marble at the top of the launcher. Let go.

3. Use a ruler to measure from the marble launcher to where the marble stopped. In the chart, write down how far it went.

4. Try your launcher on a carpet, a large piece of cardboard, and on other kinds of floors. What caused the most friction?

What caused the least?

My friction chart
Type of floor How far