A plastic roof gutter, sealed to hold water, works well for this test. The string attaches to a boat's hull and the weight drags the boat through the water. A start and finish line mark the distance for timing and a stopwatch records the speed. A photogate sensor provides a more technical option for recording the speeds. Porous materials, like wood sheet stock, need a coating to reduce water absorption.
Coatings can make the hull smoother, reducing friction, and increasing performance.
The boat can have no pointed, sharp, or loose parts that might injure children. A photogate sensor is not essential to this activity. For further information about this tool, see page 8. All rights reserved.