Make Color Powered Boats

Materials you'll need

• Styrofoam sheet
• Small paper cup
• Bendy straw
• Scissors
• Glue
• Food coloring or liquid watercolor (multiple colors)
• Water
• A bin, tub, or wading pool filled with water
• Small character cutout or sticker (optional, for your captain!)

 

Step-by-step tutorial

Step 1: Cut your styrofoam into a boat shape.

Step 2: Glue the paper cup on top of the styrofoam, near the back of the boat.

Step 3: Grab a bendy straw and cut it. Push the straw up through the bottom of the styrofoam and into the cup, then bend the flexible end outward so it sticks out from the bottom of the boat like a nozzle.

Step 4: Add a captain to your boat! Press a small character cutout or sticker into the front of the styrofoam to cheer you on.

Step 5: Build a second boat the same way so you're ready to race.

Step 6: Place your boats in the water, fill each cup with a different color of water, and watch them go. 

Learn more

When you fill the cup with colored water, it drains through the straw and shoots out the bottom — and that's what moves the boat forward. This is Newton's third law of motion: when the water pushes out in one direction, it pushes the boat in the opposite direction with equal force. It's the same idea behind jet engines and rockets. The colorful trails left in the water show exactly where your boats have been.