Compass or a large, round container
- Cut the front or back off a cereal box to make a large, flat piece of cardboard. It should be smooth and not creased or folded.
- Use a drawing compass to make a circle that is at least 6 inches in diameter. You could also trace around a large, round container that’s approximately 6 inches to make a circle.
- Cut out the circle. Find the center of the circle by using a pencil to mark the point where two diameters (the longest lines that can be drawn across a circle) intersect.
- Partially unfold a paper clip so that it’s shaped like the number 4. The outer loop of the paper clip should unbend 180 degrees and stick out straight, and the shorter inner loop should unbend 90 degrees and point down. (Like this!)
- Poke the short arm of the paper clip through the center of the cardboard disc. This point is what your top spins on. Tape the longer paper clip arm in place. If you’d like, decorate your cardboard disc.
- Grab the paper clip loop on top of the disc and give it a spin! Tape four pennies to the edge of the disc so they are across from each other and the same distance from the center. Spin and observe what happens.
Newton’s First Law of Motion states that an object in motion tends to stay in motion, until friction or another force slows it down. This is inertia. These spinning toys demonstrate that concept with rotational motion. An important part of how an object spins is how much mass it has and how far that mass is from the center, or axis of rotation. Which top has most of its mass near the center? Which top spins longer and is more stable?