Which gives a balloon the most static: hair, wool or cotton?
- 🎈 Balloons
My hypothesis
If I change what the balloon is rubbed on, then how many paper bits the balloon picks up will ______, because ______.
You fill in the blanks. Think about what rubbing moves from one thing to the other, and which things give it up most easily. A guess is a good because: the test finds out.
Change, measure, keep the same
CHANGE
what the balloon is rubbed on: Hair (clean and dry), A wool sock, A cotton T-shirt
MEASURE
how many paper bits the balloon picks up, in paper bits
KEEP THE SAME
- the same balloon
- ten rubs every time, the same way
- holding the balloon the same 2 cm above the bits
- the same 30 bits of paper
Scientists call the thing you change the independent variable and the thing you measure the dependent variable. The things you keep the same are the controls: if one of them changed too, you wouldn't know which change made the difference. Try each of the 3 levels 3 times.
What you need
- A balloon: 1, and a spare
- Paper: a scrap
- Something wool: a sock, a hat or a sweater
- A cotton T-shirt or tea towel
- Paper towels
- A stopwatch or a kitchen timer
- ✂️ Kid scissors
- 📏 A ruler
Steps
- Grown-up: A grown-up blows up the balloon and ties it.
- Test on a dry day: damp air lets the static leak away.
- Cut 30 tiny squares of paper, as big as your little fingernail, and spread them on a table.
- Rub the balloon on clean, dry hair ten times, the same way each time.
- Hold it 2 cm above the paper bits for five seconds, then lift it away.
- Count the bits stuck to the balloon, write the number down, and put them back.
- Wipe the balloon with a damp paper towel and let it dry for a minute before each new try.
- Do two more tries with hair, then three with the wool and three with the cotton.
- Find the middle number for each and draw a bar graph.
One step is a grown-up's, marked above. Write each number down straight away, in the table below, so nothing is lost.
Your results table
Name ______________________ Fair day ____________
Question: Which gives a balloon the most static: hair, wool or cotton?
I changed: Rubbed on I measured: how many paper bits the balloon picks up (paper bits)
| Rubbed on | Try 1 (paper bits) | Try 2 (paper bits) | Try 3 (paper bits) | Mean |
|---|---|---|---|---|
| Hair (clean and dry) | ||||
| A wool sock | ||||
| A cotton T-shirt |
MY GRAPH (a bar graph: rubbed on along the bottom, paper bits up the side)
What I noticed: ______________________________________________
From 4th grade, add the tries for each level and divide by how many there were: that's the mean, and it goes in the last column. Then draw a bar graph, one bar for each thing you tried.
Name ______________________ Fair day ____________
Question: Which gives a balloon the most static: hair, wool or cotton?
If I change what the balloon is rubbed on, then how many paper bits the balloon picks up will ________________, because _____________________________________________
| I CHANGE | I MEASURE | I KEEP THE SAME |
|---|---|---|
| Rubbed on: Hair (clean and dry), A wool sock, A cotton T-shirt | how many paper bits the balloon picks up (paper bits) |
|
What I think will happen, in my own words:
Name ______________________ Fair day ____________
Question: Which gives a balloon the most static: hair, wool or cotton?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Which gives a balloon the most static: hair, wool or cotton?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Which gives a balloon the most static: hair, wool or cotton?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Which gives a balloon the most static: hair, wool or cotton?
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: rub 5, 10 and 20 times on the best one, and draw a line of how the count grows.
Why it works
Rubbing moves tiny bits of electricity called electrons from one thing to the other, so the balloon ends up with an extra charge. That charge tugs on the paper bits and lifts the light ones. Hair and wool usually give up electrons easily, so the balloon often picks up more after them than after cotton.
Going further (7th and up): Change a second thing: rub 5, 10 and 20 times on the best one, and draw a line of how the count grows.
Board layout
- ❓ Question (10 × 8 in): Which gives a balloon the most static: hair, wool or cotton?
- 💭 Hypothesis (10 × 9 in): If I change what the balloon is rubbed on, then how many paper bits the balloon picks up will ______, because ______.
- 🧺 Materials (10 × 12 in): 6 things: see your list.
- 🪜 Steps (22 × 9 in): 9 steps, three tries at each level.
- 📊 Results (22 × 16 in): Your table (Rubbed on down the side, tries across) and your bar graph.
- ✅ Conclusion (10 × 14 in): My hypothesis was right / partly right / not right. I know because…
Materials to list: A balloon; Paper; Something wool: a sock, a hat or a sweater; A cotton T-shirt or tea towel; Paper towels; A stopwatch or a kitchen timer.
Bring photos or drawings of your test. Nothing wet, hot, powered or alive on the table.
This project at your grade
| 1st–3rd grade | Tries: three at each level (one is fine at a first fair). The table: levels and tries, numbers or pictures. The graph: a picture, or a simple bar graph. The conclusion: what happened, in their words. |
|---|---|
| 4th–6th grade | Tries: three at each level. The table: units in the header and a mean column. The graph: a bar graph, or a line for a number that grows. The conclusion: right, partly or not, and the numbers that show it. |
| 7th grade and up | Tries: three or more at each level. The table: a mean for every level of both tests. The graph: a graph with two lines or two sets of bars. The conclusion: the numbers, what might have gone wrong, and a next question. Second variable: rub 5, 10 and 20 times on the best one, and draw a line of how the count grows. |
From 4th grade up, the table gets a mean column. See every project for 2nd grade, or print a blank results table.
What a judge will ask
- What did you change, and what did you measure? I changed what the balloon is rubbed on and measured how many paper bits the balloon picks up, in paper bits.
- What did you keep the same, and why does that matter? I kept the same balloon and ten rubs every time, the same way the same, so the only difference was what the balloon is rubbed on.
- How many times did you test it? 3 times at each of my 3 levels.
- If you did it again, what would you change or test next? I'd rub 5, 10 and 20 times on the best one, and draw a line of how the count grows.
Make it yours
Keep this project on this device and Peabody counts down to your fair day, with a plan for each day. Nothing is sent anywhere.
Try next
- Does more air make a balloon rocket go farther?2nd–8th grade · 1 day of testing · about $1🚗 How things move · ✂️ Paper, tape and toys
- Does a longer string swing slower?4th–8th grade · 1 day of testing · free🚗 How things move · ✂️ Paper, tape and toys
🔨 From the Workshop: this project grows from a Workshop build, with picture steps of its own.
👨👩👧 For grown-ups and teachers: how much to help, the safety rules, and running a school fair. Science fair v0.16.1 · Checked .