🧱 Domino spacing and speed: the whole packet

🧱 Domino spacing and speed · 4th–8th grade · 1 day of testing · about $4 · 60 minutes a sitting

My days, if the fair is 14 days away

Count back from your fair day and write in each date. Fewer days than this? The jobs share days, in this order; nothing is skipped.

Dates from my teacher

• My question is due
• Testing starts
• My results table and graph are due
• My board is due

In this packet

1. 🗓️ My project plan
2. 💭 My hypothesis
3. 🧺 Change, measure, keep the same
4. 🪜 My steps
5. 📊 My results
6. 📓 My logbook
7. ✅ My conclusion
8. ✂️ Board titles to cut out
9. 🏅 The judge's questions and my certificate

If I change the gap between the dominoes, then how many seconds the whole line takes to fall will ________________, because _____________________________________________

What I think will happen, in my own words:

3 levels × 5 tries at each = 15 tries in all. If anything you keep the same changes, you won't know which change made the difference.

What I need

• 🁫 Dominoes, or small wooden blocks all the same size: 20
• 📄 Paper: a sheet
• 📏 A tape measure, or a long ruler
• ⏱️ A stopwatch or a kitchen timer
• ✂️ Kid scissors
• 📏 A ruler

Be safe: ✅ Nothing sharp, hot or small

1. Cut paper strips 1, 2 and 3 cm wide: they are your spacers.
2. Stand 20 dominoes in a line on a smooth table, laying the 1 cm spacer between each pair as you go.
3. Slide the spacers out carefully, so that no domino tips.
4. Measure the line from the first domino to the last, and write the length down.
5. A helper starts the timer when you tip the first domino with one finger, and stops it as the last one falls.
6. Write the time in your table. If the line stops early, stand it up again and redo it.
7. Do four more tries with the 1 cm gap, tipping the first domino the same way.
8. Make the line again with the 2 cm spacer, measure it, and do five tries.
9. Make the line with the 3 cm spacer, measure it, and do five tries.
10. Find the mean for each gap and draw a line graph.

Write each number in your results table the moment you measure it.

I changed: Gap between dominoes   I measured: how many seconds the whole line takes to fall (seconds)

MY GRAPH (a line graph: gap between dominoes along the bottom, seconds up the side)

What I noticed: ______________________________________________

Write something every day you work on it, even the days you only gather things. More days? The three-page logbook prints from peabody.kids/science-fair/templates/logbook.

My hypothesis was ☐ right ☐ partly right ☐ not right.

I know because my numbers show:

What surprised me, or what might have gone wrong (7th and up):

Next time I would test:

Idea: Change a second thing: work out each line's speed (length divided by time) and graph speed against gap. Where does the line stop working?

1. What made you want to ask this question? Say something like: I wanted to know: do dominoes fall faster when farther apart?
2. What did you think would happen, and why? Say something like: I thought changing the gap between the dominoes would change how many seconds the whole line takes to fall, and I wrote down why.
3. What did you change, and what did you measure? Say something like: I changed the gap between the dominoes (1 cm, 2 cm, 3 cm) and measured how many seconds the whole line takes to fall in seconds.
4. What did you keep the same, and why does that matter? Say something like: I kept 20 dominoes in every line and the same smooth table the same, so only the gap between the dominoes was different.
5. How many times did you test it? Say something like: 5 times at each of my 3 levels, and I found the middle number.
6. What did you find out? Show me in your numbers. Say something like: Look at my table: 1 cm and 3 cm gave different numbers, and here's the pattern.
7. Was your hypothesis right? How do you know? Say something like: My numbers show whether I was right, partly right or not, and I can show you where.
8. Did anything go wrong, or surprise you? Say something like: One try was odd, so I did it again and wrote it in my logbook.
9. If you did it again, what would you change or test next? Say something like: I'd change a second thing: work out each line's speed (length divided by time) and graph speed against gap. Where does the line stop working?