Build a paper bridge.
One sheet. A surprisingly strong idea.
Can you make a sheet of paper hold more weight without adding another sheet? Build a small bridge between two stacks of books and compare a flat deck with a folded one.
Choose a bridge activity.
Build a Paper BridgeCompare flat and folded paper across the same small gap.
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Plan My Paper BridgeSketch a bridge and decide how you will compare it fairly.
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My Bridge PredictionPredict what will happen before putting blocks on your bridge.
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My Bridge Test ResultsRecord what your flat and folded bridges actually hold.
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Improve My Paper BridgeChange one feature and see what happens in another test.
Draw · Type · SaveLet's make it happen.
Set the supports
Place two low, equal-height book stacks on a low surface. Leave a small gap with enough paper to rest securely on both stacks.
Test flat paper
Lay one sheet across the gap. Add blocks gently at the centre, one at a time. Stop at noticeable bending or slipping.
Record the result
Count only blocks held before bending or slipping. Record zero if the first block causes this. Describe what happened.
Fold another sheet
Use matching paper. Make alternating narrow accordion folds so ridges run from one support to the other. Keep both ends supported.
Compare fairly
Keep the gap, blocks and loading position the same. Use the same stopping rule, record the result and compare.
Improve one feature
Change one fold feature, test again and explain what you learned.
What's happening here?
Folding changes the shape of the paper's cross-section. Ridges running across the gap can resist bending better than a flat sheet. The result also depends on the paper, fold shape and where you place the load.
Keep the wondering going.
- What did you keep the same to make the comparison fair?
- Where did each bridge start to bend?
- Would turning the folds across the other direction change the result?
Make it work for you.
Keep it simple
Fold the paper together. Focus on comparing flat and folded, then count the blocks aloud.
Take it further
Repeat each design three times with fresh paper. Compare the results and explain why the numbers might vary.
Not quite going to plan?
Bridge slips off? Make the gap smaller for both designs and restart the comparison. Folds flattening? Sharpen the creases and check that the ridges run from support to support.
My bridge test
Sketch each design and record how many blocks it held before it bent.
Image · prints on A4 or Letter using “fit to page”. Plain paper works just as well.
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