demonstrations:inseparable_books

Inseparable Books

Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required

Categories: Force

Alternative titles: Friction Between Notebook Pages

Summary

Two notebooks are interleaved page by page and become nearly impossible to pull apart.

Procedure

  1. Place two notebooks on a flat surface with their bindings facing inward.
  2. Overlap the covers so they are completely aligned.
  3. Starting near the spine, alternate one page from each notebook, interleaving them page by page until the books are fully intertwined.
  4. Hold the notebooks just inside the bindings and attempt to pull them apart.
  5. Try with a partner pulling one notebook while you pull the other. Notice how the pages hold tightly together.

Inseparable Books Experiment - Kids Fun Science:


📄🎞️ Inseparable Books - Steve Spangler: https://stevespangler.com/experiments/inseparable-books/

Variations

  • Try using different types of paper (glossy, thin, thick) to compare how friction changes.
  • Increase or decrease the number of interleaved pages to test the effect on pulling difficulty.
  • Use smaller or larger notebooks to see if size affects the result.

Safety Precautions

  • Pull carefully to avoid sudden slips that might cause someone to fall or bump into something.

Questions to Consider

  • Why does interleaving many pages produce so much friction?
  • How does the number of contact surfaces affect the total friction?
  • What role does friction play in everyday activities (e.g., walking, driving, holding objects)?
  • Could lubrication between the pages reduce the friction and make the books separable?