🌡️ Which colour of paper warms up most in the sun?

My hypothesis

If I change the colour of the paper, then how many degrees the thermometer under the paper warms in 20 minutes will ______, because ______.

🔊 You fill in the blanks. Think about why some colours look bright and some look dark, and where the light that isn't bounced back goes. A guess is a good because: the test finds out.

Change, measure, keep the same

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 4 levels 3 times.

What you need

• 🌡️ A thermometer (digital, or the red-liquid kind): 4, all the same kind
• 📄 Paper: 1 sheet each of white, yellow, blue and black
• 📦 Flat cardboard: a flat piece to lay them on
• ⏱️ A stopwatch or a kitchen timer
• 🩹 Tape

Steps

1. Fold each sheet of paper in half to make a pocket.🔊
2. Slide a thermometer into each pocket so its tip sits in the middle, and tape the sides shut.🔊
3. Lay all four side by side on the cardboard in the shade, and write down each starting temperature.🔊
4. Carry the cardboard into full sun, all at once, and start the timer.🔊
5. After 20 minutes, read each thermometer and write it down.🔊
6. Take away the starting number to find how much each one warmed.🔊
7. Move them back into the shade for 15 minutes to cool, then do it two more times.🔊
8. Never look at the sun: look down at your thermometers.🔊
9. Find the mean warming for each colour 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

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.

Why it works

🔊 Sunlight carries energy. White paper bounces most of the light back, which is why it looks bright, while black paper soaks most of it up and turns it into warmth. Colours in between soak up some colours of light and bounce others, so they usually warm somewhere in the middle.

Going further (7th and up): Change a second thing: test every colour in the morning, at noon and in the afternoon, and draw a line for each colour.

Board layout

This project at your grade

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 the colour of the paper and measured how many degrees the thermometer under the paper warms in 20 minutes, in degrees.
• What did you keep the same, and why does that matter? I kept the same kind of thermometer in each pocket and the same size of paper, folded the same way the same, so the only difference was the colour of the paper.
• How many times did you test it? 3 times at each of my 4 levels.
• If you did it again, what would you change or test next? I'd test every colour in the morning, at noon and in the afternoon, and draw a line for each colour.

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

• ☀️ Where does a puddle dry fastest: sun, shade or wind?2nd–6th grade · 2 days of testing · free🌦️ Growing and weather · 🌱 Outside and plants
• 🧊 Which cup keeps an ice cube from melting longest?1st–7th grade · 1 day of testing · about $1🧪 Water, ice and mixing · 🧂 Kitchen things