Oobleck: Solid or Liquid?
It feels solid under quick force but flows slowly.
Teaching & key ideas
What you do: Tap quickly, then slowly let fingers/object sink.
What students see: It feels solid under quick force but flows slowly.
Why it works: Suspended particles temporarily jam under rapid shear.
Question to ask: Why does moving faster make it feel harder?
Lesson flow
Predict → demonstrate → observe → briefly explain → ask: Why does moving faster make it feel harder?