Spinning Button Aerodynamics
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See more activities in: Third Grade, Physical Science

With a button, string and a stopwatch, children can see, hear and measure aerodynamics in action! In this energy transfer activity, your child will compare the spin duration of a button strung on different kinds of string. Two key elements of the scientific method are introduced: how to record results of an experiment on a data chart and how to use data to support a conclusion.

What You Need:

  • Flat button with 2 holes
  • 5-10 kinds of string (thread, yarn, fishing line, kite string, dental floss, waxed thread, twine, etc.)
  • Measuring tape
  • Stopwatch
  • Paper and pen

What You Do:

  1. Ask your child to cut into 4-foot lengths.
  2. Have your child thread string through one hole and back through the other to make a loop then double-knot it.
  3. Invite your child to hold one end of loop in each hand, with button in middle.
  4. Have her swing button in a circular motion to wind string.
  5. Have her keep winding until she can feel the thread between her fingertips twist.
  6. Then, she should gently pull her hands apart (no more than an inch), to start unwinding. In less than a second, she will need to give it a little slack so it can re-wind, then repeat in rhythm with the button's winding/unwinding.
  7. Hypothesize. Invite her to predict which strings are more aerodynamic (button spins longer) and which create friction (button spins less).
  8. Ask your child to record her hypothesis (prediction), number the strings, and arrange them for testing.
  9. Ask your child to decide on number of winds and winding direction, then wind each string the same way.
  10. Test. You'll handle the stopwatch while your child tests. She should say "Go!" when first winding is done and "Stop!" when button stops. Show her the elapsed time, so she can record data. Invite her to test each string three times to establish an average (divide sum of elapsed times by 3).
  11. Review the data together. What do they have in common? Does the data prove her hypothesis? If her prediction was that buttons spin longer on thin threads, do elapsed times show this?