- Stop watch or timer (found on smart phones)
- Ramp (sliding board, piece of plywood or heavy cardboard)
- Smooth flat surface (driveway, patio, sidewalk, wood floor)
- Sandpaper, mud, water, sand, double-sided tape
- Miniature toy cars, marbles, small balls
Friction: a force that resists motion
Flat Surface Fun
Begin with a small toy car or other toy that rolls. On a flat surface, roll the car to see how far it goes. Now time it to see how fast it goes to a designated point.
Next, introduce the word friction. Say, “Imagine that you are trying to roll the car in deep snow, thick mud or on gravel. These things would slow you down. This is friction.
Think of ways we can demonstrate the effect of friction:
- Add sand to the surface
- Add mud to the surface
- Add water to the surface
- Tape stripes of cardboard or sandpaper to create bumps on the surface
- Add liquid dish soap or cooking oil to the surface
Which surface caused the most friction? Can the child think of other ways to cause friction on the smooth surface?
Ramp It Up
Make a ramp using a sliding board, piece of plywood or other hard material. Prop it up on one end with a stack of books or similar objects. Use a ruler as a starting gate to allow the objects to be released naturally instead of being pushed.
Place an object such as a marble or small ball behind the ruler at the top of the ramp. Lift the ruler to release it. Time it. Then add items to cause friction on the ramp such as sandpaper or double-sided tape. How does the time compare? Use some of the same ideas that you used on the flat surface.
Can you think of ways that friction would be a factor when you are riding your bike, scooter or skateboard? Would it be easier to play soccer or football on a dry or muddy field? If you were just wearing socks on your feet, would you slide faster on carpet or wood flooring?
Playtime can be learning time with just a little planning. The added feature is spending time together.
- Physics 4 Kids: Motion – Friction
- Science Kids: Friction
- May, Vicki V. 3-D Engineering: Design and Build Your Own Prototypes. Nomad Press, 2015.