Pulleys serve as a key component of many machines, lifting loads big and small. Students see firsthand how to use a pulley to transfer force or increase speed while building 8 machines. They start with a simple material lift pulley or stationary bike, and then move on to more complex pulley systems including a crane bridge and a windmill. Demonstrations also show students how the pulley's size affects the amount of force and speed produced. Included guide is easy to follow and features detailed explanations and quizzes about the experiments. Kit includes 108 pieces. Recommended for Elementary and up.