🎱 Marble run height and speed: the whole packet

🎱 Marble run height and speed · 3rd–8th grade · 1 day of testing · free · 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 how high up the run the marble starts, then how fast the marble crosses 2 m of floor will ________________, because _____________________________________________

What I think will happen, in my own words:

3 levels × 3 tries at each = 9 tries in all. If anything you keep the same changes, you won't know which change made the difference.

What I need

• 🧻 Cardboard tubes: 3
• 🔮 A marble
• 🩹 Masking tape, to mark lines
• 📏 A tape measure, or a long ruler
• ⏱️ A stopwatch or a kitchen timer
• ✂️ Kid scissors
• 🩹 Tape

Be safe: 👶 Small parts

1. Cut three cardboard tubes in half the long way to make six slides.
2. Tape the slides down a wall in a zigzag, the last one ending right at a hard floor.
3. Mark the three start spots with masking tape: the slides 40, 80 and 120 cm up.
4. Put a tape line on the floor where the run ends, and another 2 m farther on.
5. Lay a folded towel past the second line to stop the marble.
6. Set the marble in the run at 40 cm and let go without a push.
7. A helper starts the timer as it crosses the first line and stops it at the second.
8. Write the time down, then do it two more times.
9. Do three runs from 80 cm and three from 120 cm.
10. Work out each speed: 200 divided by the seconds gives cm per second.
11. Find the mean speed for each height and draw a line graph.

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

I changed: Start height   I measured: how fast the marble crosses 2 m of floor (cm per second)

MY GRAPH (a line graph: start height along the bottom, cm per second 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: tilt every slide more steeply, run all three heights again, and draw both lines on one graph.

1. What made you want to ask this question? Say something like: I wanted to know: does a higher start make a marble roll faster?
2. What did you think would happen, and why? Say something like: I thought changing how high up the run the marble starts would change how fast the marble crosses 2 m of floor, and I wrote down why.
3. What did you change, and what did you measure? Say something like: I changed how high up the run the marble starts (40 cm, 80 cm, 120 cm) and measured how fast the marble crosses 2 m of floor in cm per second.
4. What did you keep the same, and why does that matter? Say something like: I kept the same marble and letting go without a push the same, so only how high up the run the marble starts was different.
5. How many times did you test it? Say something like: 3 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: 40 cm and 120 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: tilt every slide more steeply, run all three heights again, and draw both lines on one graph.