Spinning Seed Challenge

Grade Level: K-6
Time: 30-40 minutes
Group Size: Individual or pairs

Materials Needed (per student):

• 2-3 strips of paper (about 3” x 8” each — a strip cut from a sheet of printer paper works perfectly)
• Scissors
• 1-2 paper clips
• Ruler
• Pencil for marking
• Timer (1 per class)
• Drop point at least 6 feet high (standing on a chair, balcony, or top of a stairwell)

The Challenge:

Design a paper spinning seed (like a maple key) that stays in the air as long as possible when dropped from the same height. The longest airborne time wins.

How Spinning Seeds Work:

Maple trees drop seeds called samaras (or “helicopters”). As a samara falls, the angled wing catches air and creates lift on one side, causing the whole seed to spin. That spinning slows the fall dramatically, giving the seed time to drift far from the parent tree.

Your challenge: engineer the same effect from paper.

Step-by-Step Instructions:

Setup (5 minutes):

1. Drop a flat strip of paper from your drop height and time how long it takes to land. Write this as the “flat paper” baseline.
2. Show students a real maple key if you can find one, or draw one on the board.
3. Ask: “What shape makes this spin? Why does spinning slow it down?”

Building Phase (15-20 minutes):

Basic spinning seed design:

Step 1: Mark your paper strip

1. Hold the strip vertically
2. Measure down about 1/3 of the strip from the top and draw a horizontal line
3. This line is where your “wing” will split from the “body”

Step 2: Cut the wing

1. From the top of the strip, cut down the center to your line
2. You now have two flaps at the top and a single body below

Step 3: Fold the wings

1. Fold one flap toward you and one away from you
2. The two wings should angle in opposite directions — this is what causes the spin

Step 4: Add weight

1. Fold the bottom 1 inch of the body up once or twice to make it heavier
2. OR clip a paper clip to the bottom of the body
3. The heavier bottom keeps the seed oriented correctly: wings up, weight down

Step 5: Test drop

1. Hold the seed by the weight end, wings pointing up
2. Drop (do not throw) from the same height each time
3. It should spin and flutter down slowly

Adjustments:

• Not spinning: Check that the two wings angle in opposite directions; they must not both point the same way
• Spinning but falling fast: Wings may be too narrow; try a wider strip
• Flipping upside down: Add more weight to the bottom
• Spinning in the wrong direction: Reverse the fold direction on both wings

Teacher Tips:

• This activity works beautifully as an individual build — each student makes 2-3 iterations
• The drop height matters a lot: the higher the better for seeing differences
• Students often want to make the wings huge, but very wide wings can cause the seed to flutter chaotically rather than spin cleanly
• Encourage students to try small changes one at a time so they can see what each change does

Testing Phase (10 minutes):

1. Students drop their best design 3 times from the same height
2. Timer calls out when the seed lands
3. Record best time
4. Class compares results and discusses what the longest-flying seeds had in common

Gallery round: Have students bring their best designs forward and drop them all at once. The class watches and calls out what they see.

Learning Objectives:

• Autorotation: How asymmetric wing shape generates spin during a fall
• Drag: How spin increases air resistance and slows descent
• Weight and balance: Why heavier bottoms keep the seed oriented correctly
• Iteration: Small design changes have noticeable effects on flight

Differentiation:

• Easier (K-2): Pre-cut the wing split; students only fold the wings and add the paper clip
• Harder (Grades 4-6): Students must try at least three different wing angles and record which flew longest; write one sentence explaining what they noticed
• Extension: Cut two designs — one with short wings, one with long wings — and compare drop times; ask which travels farther sideways as well as hanging in the air longest

Discussion Questions:

• Why does the seed spin instead of just falling straight down?
• What did the seeds that stayed up longest have in common?
• The maple tree uses this to spread its seeds far from the parent tree. Why does staying in the air longer help with that?
• Can you think of other seeds or natural objects that use a similar trick?

Common Problems and Solutions:

Real-World Connections:

• Maple, ash, and sycamore trees all use spinning seeds to spread far from the parent tree
• Helicopter blades use the same rotating-wing principle to generate lift
• Autogyros (a type of early aircraft) used an unpowered spinning rotor to stay aloft, much like a spinning seed
• The descent capsules of some early spacecraft used autorotation to slow down