Build a Paddle Boat

This paddle boat uses stored energy from a rubber band to turn the paddles and move the boat through the water. The energy turns into motion, pushing the boat forward. Experiment with different designs and paddle sizes to see how they affect how fast and far the boat goes!

Materials needed:

  • 1 Large Craft Stick
  • 6 Small Craft Sticks
  • 1 Rubber Band
  • 1/2 Straw
  • Tape or Hot Glue

This paddle boat uses several forces to move through the water. Here are the key forces at work:

Stored Energy (Elastic Potential Energy)
  • When you twist or stretch a rubber band, you store energy inside it. This is called elastic potential energy, because the rubber band wants to snap back to its original shape.
  • As you wind the paddles, you are stretching or twisting the rubber band. The more you wind, the more energy is stored!
Motion (Kinetic Energy)
  • When you release the stretched rubber band, the stored energy turns into kinetic energy, which is the energy of motion.
  • The more force you use, the faster the paddles will spin!
Force (Push)
  • When force moves an object away from something, that’s a push.
  • When you let go of the paddle, all the stored energy is released quickly. This creates a force that turns the paddles.
  • As the paddles spin and push against the water, they create a pushing force that moves the boat forward.
Water Resistance (Drag)
  • As the boat moves through the water, it pushes against the water, which slows it down.
  • This is called water resistance, or drag.
  • A boat with less drag will move faster and farther.
Buoyancy
  • The boat floats because of buoyancy.
  • This force keeps the boat from sinking and allows it to sit on top of the water.
  • What can you add to the bottom of the boat to improve its buoyancy?
Balance and Design
  • The way you design the boat affects how well it moves.
  • A balanced boat with properly placed paddles and a strong structure will move faster and more smoothly.

By adjusting the rubber band tension, paddle design, and boat shape, you can experiment with these forces to make your paddle boat go faster and farther!