Choose the sheet for the learner's age. Each prints on a single page. Build the project first, then fill it in together.
Ages 5-7: Draw & tell
Name: ______________________Date: ____________
Homemade Science with Bruce Yeany · String Shooter · Ages 5-7
Flying String
Blow your string shooter, then draw and circle.
1. Draw your straw and the flying loop. Draw an arrow showing which way the yarn moves.
2. When you blow, the yarn goes...
◯ into the hole◯ out of the hole
3. Blowing harder makes the loop...
◯ fly higher◯ fall down
4. Which flies better?
◯ fuzzy yarn◯ smooth string
5. One word for how the loop looks when it flies:
Ages 8-10: Predict, test & record
Name: ______________________Date: ____________
Homemade Science with Bruce Yeany · String Shooter · Ages 8-10
String Shooter Test Lab
Make a guess, test your shooter, and record what happens.
1. Predict: when you blow into the straw, the air at the side hole will...
◯ puff out of the hole◯ get pulled into the hole◯ do nothing
2. Try three ways of blowing or aiming. What does the loop do?
Try
What I changed
What the loop did
3. Without the dent at the edge of the hole, the yarn...
◯ flies better◯ barely moves◯ flies the same
4. What did you find out about making the loop fly well?
5. Why do you think fuzzy yarn flies better than smooth string?
Ages 11-14: Explain & design your own test
Name: ______________________Date: ____________
Homemade Science with Bruce Yeany · String Shooter · Ages 11-14
Explaining the String Shooter
Use your shooter and the ideas in "What's going on?" to explain and test it.
1. Use the words constriction and pressure to explain why air goes into the side hole instead of blowing out.
2. What drives the yarn forward inside the straw?
◯ Drag from the fast-moving air◯ Magnetism◯ Gravity pulling it out
3. Once the yarn leaves the straw, why does it keep moving forward? Name the idea.
4. Design a fair test of which string flies best.
What I change
What I measure
What I keep the same
5. Rope does not work in a string shooter. Explain why, using the words drag and gravity.
6. Where else does fast-moving air in a narrow spot pull or push things in?
Answer guide for grown-ups
Homemade Science with Bruce Yeany · String Shooter · Answer guide
Answer guide
Ages 5-7: Flying String
Open answer: look for effort and careful observation.
into the hole
fly higher
fuzzy yarn
Any fair word, such as loop, wavy, springy or fast.
Ages 8-10: String Shooter Test Lab
Get pulled into the hole (with the dent in place).
Open answer: look for effort and careful observation.
barely moves
Blow hard and steady, keep the dent at the back edge of the hole, and use light, fuzzy yarn; the loop holds its shape in any direction while it moves fast.
The little fibers catch more air, so the moving air pushes on it more (more drag and more lift) without adding much weight.
Ages 11-14: Explaining the String Shooter
The dent narrows the straw, so the air speeds up as it passes the hole. Faster air has lower pressure (Bernoulli's principle), so the higher-pressure air outside pushes in through the hole, carrying the yarn into the airflow.
Drag from the fast-moving air
Inertia: a moving object keeps moving until a force (the pull of the rest of the loop, air drag, gravity) changes its motion.
Change: the type of string. Measure: how high or far the loop reaches, or whether it stays up. Keep the same: loop length, straw, hole and dent, how hard you blow.
Rope is too heavy for its surface area, so the drag and lift from the air are too small to beat gravity, and it falls.
Examples: a shop-vac pipe drawing in sugar or string, a venturi or atomizer sprayer, a carburetor, a perfume or paint sprayer.