Which warms up most in the sun: soil, sand or water?
- 🌳 Outside
- 😎 Never look at the sun
My hypothesis
If I change what is in the cup, then how many degrees the top warms in one hour will ______, because ______.
You fill in the blanks. Think about how deep the sun's warmth gets into each one. A guess is a good because: the test finds out.
Change, measure, keep the same
CHANGE
what is in the cup: Soil, Sand, Water
MEASURE
how many degrees the top warms in one hour, in degrees
KEEP THE SAME
- cups filled to the same line
- all the cups side by side in the same sunny spot
- the thermometer's tip just under the top, the same depth every time
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, the same size
- Potting soil: enough for 3 cups
- Sand (from a sandbox, or play sand): enough for 3 cups
- Water from the tap: enough for 3 cups
- A thermometer (digital, or the red-liquid kind)
- Masking tape, to mark lines
- A baking tray or big plate
- A stopwatch or a kitchen timer
Steps
- Put a strip of tape around nine cups at the same height, near the top.
- Fill three cups with soil, three with sand and three with water, up to the tape.
- Leave them inside for an hour so they all start at room temperature.
- Read the thermometer just under the top of each cup, and write it down.
- Set the cups side by side on a tray in a sunny spot, and start the timer.
- After one hour, read each cup again the same way.
- Take the first number away from the second: that is how many degrees it warmed.
- Draw a bar graph with one bar for soil, one for sand and one for water.
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: Which warms up most in the sun: soil, sand or water?
I changed: What is in the cup I measured: how many degrees the top warms in one hour (degrees)
| What is in the cup | Try 1 (degrees) | Try 2 (degrees) | Try 3 (degrees) | Mean |
|---|---|---|---|---|
| Soil | ||||
| Sand | ||||
| Water |
MY GRAPH (a bar graph: what is in the cup along the bottom, degrees 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 warms up most in the sun: soil, sand or water?
If I change what is in the cup, then how many degrees the top warms in one hour will ________________, because _____________________________________________
| I CHANGE | I MEASURE | I KEEP THE SAME |
|---|---|---|
| What is in the cup: Soil, Sand, Water | how many degrees the top warms in one hour (degrees) |
|
What I think will happen, in my own words:
Name ______________________ Fair day ____________
Question: Which warms up most in the sun: soil, sand or water?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Which warms up most in the sun: soil, sand or water?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Which warms up most in the sun: soil, sand or water?
| Date | What I did | What I saw | What I think |
|---|---|---|---|
Name ______________________ Fair day ____________
Question: Which warms up most in the sun: soil, sand or water?
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: read each cup at the top and at the bottom, and graph both depths side by side.
Why it works
Sunlight warms only the top of soil or sand, so its warmth stays near the surface, where you read it. In water the warmth spreads down through all of it, so the top of the water usually warms the least.
Going further (7th and up): Change a second thing: read each cup at the top and at the bottom, and graph both depths side by side.
Board layout
- ❓ Question (10 × 8 in): Which warms up most in the sun: soil, sand or water?
- 💭 Hypothesis (10 × 9 in): If I change what is in the cup, then how many degrees the top warms in one hour will ______, because ______.
- 🧺 Materials (10 × 12 in): 8 things: see your list.
- 🪜 Steps (22 × 9 in): 8 steps, three tries at each level.
- 📊 Results (22 × 16 in): Your table (What is 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; Potting soil; Sand (from a sandbox, or play sand); Water from the tap; A thermometer (digital, or the red-liquid kind); Masking tape, to mark lines; 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. |
From 4th grade up, the table gets a mean column. See every project for 1st grade, or print a blank results table.
What a judge will ask
- What did you change, and what did you measure? I changed what is in the cup and measured how many degrees the top warms in one hour, in degrees.
- What did you keep the same, and why does that matter? I kept cups filled to the same line and all the cups side by side in the same sunny spot the same, so the only difference was what is in the cup.
- 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 read each cup at the top and at the bottom, and graph both depths side by side.
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
👨👩👧 For grown-ups and teachers: how much to help, the safety rules, and running a school fair. Science fair v0.16.1 · Checked .