Classroom mode

Run it in class

Why do your shoes grip the floor but slip on ice?

Show of hands — before you project anything

Compare the shared ramp demand with each covered sample before choosing an option.

  • A Way more than you'd guess
  • B About what you'd guess
  • C Way less than you'd guess

Count the votes out loud. Hold them to it — then watch.

Project it (fullscreen)

Discussion prompts

  • Compare the shared ramp demand with each covered sample before choosing an option.
  • Explain why the gate is a new application even though the threshold rule was practiced earlier.
  • List conditions that could change a contact pair without changing the visible ramp angle.

Where it shows up in real life

  • A boot on a frozen patch versus the same boot on a dry walkway
  • A car tire braking on dry, wet, or icy pavement
  • A skate designed to glide while a climbing shoe is designed to grip

A prediction-first worksheet — no answer key.

zero prep · no login · any projector

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