Choose the sheet for the learner's age. Each prints on a single page. Build the project first, then fill it in together.
Ages 5-7: Draw & tell
Name: ______________________Date: ____________
Homemade Science with Bruce Yeany · Sand Pendulum Art · Ages 5-7
My Sand Drawing
Watch your bottle swing and draw what the sand makes.
1. Draw your sand bottle hanging from its Y of strings.
2. Where does the sand come out?
◯ The cap◯ The top◯ The side
3. Draw the shape the sand made.
4. Over time, did the loops get bigger or smaller?
◯ Bigger◯ Smaller
5. What does your sand shape look like?
Ages 8-10: Predict, test & record
Name: ______________________Date: ____________
Homemade Science with Bruce Yeany · Sand Pendulum Art · Ages 8-10
Two Swings, One Bottle
Time your pendulum both ways, then see what pattern it draws.
1. Predict: which way will the bottle swing faster?
◯ Along the line between the hooks◯ Across the line between the hooks◯ Both the same
2. Time 10 full swings (over and back) each way. Divide by 10 to get one swing.
Direction
Time for 10 swings
Time for 1 swing
3. What did you find out? Which way was faster?
4. Why do you think one way is faster? (Hint: watch which strings move.)
5. Move the knot and draw a quick sketch of each pattern.
Where the knot was
Sketch of the pattern
Ages 11-14: Explain & design your own test
Name: ______________________Date: ____________
Homemade Science with Bruce Yeany · Sand Pendulum Art · Ages 11-14
Lissajous Patterns with a Y-Pendulum
Use your sand pendulum to test how string length controls the pattern.
1. Define period. Then explain why one pendulum on a Y-string has two different periods.
2. Why do the loops spiral inward and fill in toward the center?
3. In a test where you move the knot of the Y, name the variable you change, the variable you measure, and two things you keep the same.
4. Design a fair test: try 3 knot positions. Record both periods and sketch each pattern.
Knot position
Period across (s)
Period along (s)
Pattern sketch
5. If you used a heavier bob on the same strings, the period would:
◯ Get longer◯ Get shorter◯ Stay about the same
6. Where else do you see a pendulum or a swinging motion used or noticed in real life?
Answer guide for grown-ups
Homemade Science with Bruce Yeany · Sand Pendulum Art · Answer guide
Answer guide
Ages 5-7: My Sand Drawing
Open answer: look for effort and careful observation.
The cap
Open answer: look for effort and careful observation.
Smaller
Any description (loops, circles, a pretzel, a figure-eight, etc.)
Ages 8-10: Two Swings, One Bottle
Any prediction is fine; it is tested next. (Result: along the line between the hooks is faster.)
Open answer: look for effort and careful observation.
Swinging along the line between the hooks was faster (shorter period), about 2 s vs 2.5 s in Bruce's room; home numbers will differ.
Along the line between the hooks, only the bottom string swings, so it acts like a shorter pendulum, and shorter pendulums swing faster.
Open answer: look for effort and careful observation.
Ages 11-14: Lissajous Patterns with a Y-Pendulum
Period = time for one full swing over and back. Across the hooks' line the whole Y swings from the ceiling (long length, long period); along that line the V can't move, so only the strand below the knot swings (short length, short period).
Friction (air and strings) keeps taking energy, so each swing is smaller and the trace closes in toward the center.
Change: knot position (length of the lower strand). Measure: the two periods and/or the pattern. Keep the same: the bob and amount of sand, total string length, how you release it, height above the surface.
Open answer: look for effort and careful observation.
Stay about the same (mass doesn't set a pendulum's period; length does).
Examples: a playground swing, a grandfather clock, a wrecking ball, a swinging door sign.