This nifty motor boat is a simple-to-make attraction. It uses a rubber band under tension to propel a small motor. This pushes the raft/boat across the surface of water pretty quickly. Follow these instructions to make your own!
27 Popsicle sticks
Small pool/bin to hold at least 1.5 inches of water
2 rubber bands
Hot glue gun and glue
Step 1: Build the Raft
Place 12 4.5'' Popsicle sticks side by side. Glue three sticks perpendicular to hold them in place.This will be the body of the boat.
Step 2: Build the Beams for the Motor
Glue two Popsicle sticks as shown in Image #1. Then cut two Popsicle sticks so it fits without overlapping onto the raft (cut off about 1/2 an inch). Glue this to the attached beams (Image #2). Then glue two more full-size Popsicle sticks to the top of the raft as shown in Image #3.
Step 3: Build the Motor
Cut two Popsicle sticks in half. Use three halves to make the motor. Cut sticks the size of the width of the motor to attach (see Image). From our tests, this size motor was the fastest.
Step 4: Add the Rubberband
Glue the center of a rubber band to both sides of the motor. Make sure the rubber band fits somewhat snugly between the beams, but it does not need to be too tight.
Step 5: Let It Loose!
Wind up the motor, winding backwards. Set the boat on the surface of water and let it go. The paddle will spin, propelling the boat.
Step 6: Science Explanation!
This peachy boat (all boats, in fact) floats due to Archimedes' Principle, which states that objects float because the buoyancy force equals the force of gravity and, therefore, the buoyancy force equals the weight of the water displaced, which is equal to the weight (or Fg) of the object. Many people think that objects float because the density of the object is less than the density of water, but this is incorrect. After all, if this was the case, how could a steel boat float?
Step 7: Test Results
You're in luck. We took some data on this boat. To test, we built a motor paddle that was twice the size of the motor listed above in the instructions. Then, we put the boat in the water and measured its speed separately with different motors.
To be consistent, we wound each motor up 20 times and the course length was 0.5 motors. We took data on each motor three times each.
Here's what we found:
Small Motor, average speed: 0.195 m/s (0.44 mph)
Large Motor, average speed: 0.173 m/s (0.39 mph)
Although it seems like a small difference, the difference in time between the motors was big for such a small distance. Follow our instructions to make the boat fitted with a small motor!