Does a colder cup get more drops on its outside?
- 💧 Water
My hypothesis
If I change how cold the water in the cup is, then how many drops are on the cup's outside, inside a small square, after ten minutes will ______, because ______.
You fill in the blanks. Think about where the drops could come from when the cup does not leak, and what is in the air around it. A guess is a good because: the test finds out.
Change, measure, keep the same
CHANGE
how cold the water in the cup is: Ice water, Fridge-cold water, Room-temperature water
MEASURE
how many drops are on the cup's outside, inside a small square, after ten minutes, in drops
KEEP THE SAME
- the same kind of cup
- the same amount of water in every cup
- the same room, away from the sun
- counting in a 3 cm square on each cup after ten minutes
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
- Clear plastic cups, all the same size: 9, all the same size
- Cold water from the fridge
- Water from the tap: left in the room for an hour
- Ice cubes, all from the same tray: 9 cubes
- A measuring cup
- Masking tape, to mark lines
- Paper towels
- A baking tray or big plate
- A stopwatch or a kitchen timer
- 📏 A ruler
Steps
- Dry the outside of nine clear cups with a paper towel.
- Frame a 3 cm square on the side of each cup with four short strips of masking tape.
- Write ice, fridge or room on a bit of tape near each cup's rim, three of each.
- Pour half a cup of room-temperature tap water into each of the three room cups.
- Pour half a cup of fridge-cold water into each of the three fridge cups.
- Pour half a cup of fridge-cold water into each of the three ice cups, and add three ice cubes to each.
- Set all nine cups on a tray, away from the sun, and start the timer.
- Wait ten minutes and don't touch the outsides of the cups.
- Count the drops inside each tape square and write the numbers in your results table.
- Find the mean drops for each kind of water and draw a bar graph.
Every step is one you can do yourself, with a grown-up nearby. Write each number down straight away, in the table below, so nothing is lost.
Your results table
Name ______________________ Fair day ____________
Question: Does a colder cup get more drops on its outside?
I changed: Water in the cup I measured: how many drops are on the cup's outside, inside a small square, after ten minutes (drops)
| Water in the cup | Try 1 (drops) | Try 2 (drops) | Try 3 (drops) | Mean |
|---|---|---|---|---|
| Ice water | ||||
| Fridge-cold water | ||||
| Room-temperature water |
MY GRAPH (a bar graph: water in the cup along the bottom, drops 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: Does a colder cup get more drops on its outside?
If I change how cold the water in the cup is, then how many drops are on the cup's outside, inside a small square, after ten minutes will ________________, because _____________________________________________
| I CHANGE | I MEASURE | I KEEP THE SAME |
|---|---|---|
| Water in the cup: Ice water, Fridge-cold water, Room-temperature water | how many drops are on the cup's outside, inside a small square, after ten minutes (drops) |
|
What I think will happen, in my own words:
Name ______________________ Fair day ____________
Question: Does a colder cup get more drops on its outside?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Does a colder cup get more drops on its outside?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Does a colder cup get more drops on its outside?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Does a colder cup get more drops on its outside?
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: test the three kinds of water in a steamy bathroom after a shower and in a dry bedroom, and graph the drops for each room.
Why it works
The air around you holds invisible water vapour. When that air touches a cold cup it cools, can't hold as much vapour, and some of it turns into tiny drops on the outside. A colder cup cools the air more, so it usually gets more drops, and they come from the air, not from the water inside.
Going further (7th and up): Change a second thing: test the three kinds of water in a steamy bathroom after a shower and in a dry bedroom, and graph the drops for each room.
Board layout
- ❓ Question (10 × 8 in): Does a colder cup get more drops on its outside?
- 💭 Hypothesis (10 × 9 in): If I change how cold the water in the cup is, then how many drops are on the cup's outside, inside a small square, after ten minutes will ______, because ______.
- 🧺 Materials (10 × 12 in): 9 things: see your list.
- 🪜 Steps (22 × 9 in): 10 steps, three tries at each level.
- 📊 Results (22 × 16 in): Your table (Water in the cup 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: Clear plastic cups, all the same size; Cold water from the fridge; Water from the tap; Ice cubes, all from the same tray; A measuring cup; Masking tape, to mark lines; Paper towels; A baking tray or big plate; 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: test the three kinds of water in a steamy bathroom after a shower and in a dry bedroom, and graph the drops for each room. |
From 4th grade up, the table gets a mean column. See every project for 3rd grade, or print a blank results table.
What a judge will ask
- What did you change, and what did you measure? I changed how cold the water in the cup is and measured how many drops are on the cup's outside, inside a small square, after ten minutes, in drops.
- What did you keep the same, and why does that matter? I kept the same kind of cup and the same amount of water in every cup the same, so the only difference was how cold the water in the cup is.
- 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 test the three kinds of water in a steamy bathroom after a shower and in a dry bedroom, and graph the drops for each room.
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.
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