Book 26, Question 133
Can you build a car pushed by a paper sail?
Yes!
Sailboats on water use wind, and so can a little car on land. Build a small car with bottle-cap wheels on straw axles, and tape on a paper sail held by a straw mast. Blow gently from behind or use a hand fan. A bigger sail catches more wind, but it also adds weight. Try different sail sizes and shapes. Which version goes the farthest? That is how inventors improve ideas.