Classroom mode

Run it in class

Why does a ball on a string fly off the second you let go?

Show of hands — before you project anything

Predict first: when the string is cut, will the ball go straight outward from the center or sideways? Vote, then watch.

  • 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

  • Predict first: when the string is cut, will the ball go straight outward from the center or sideways? Vote, then watch.
  • If there is no force pushing the ball outward, what is the only real force acting on it while it circles? Where does that force point?
  • Predict what changes about the ball's path the instant the string is gone, and what happens a moment later because of gravity.

Where it shows up in real life

  • A hammer thrower or discus athlete spinning and releasing at sports day
  • Swinging a conker or yo-yo on a string, or a bucket of water on a rope
  • Letting go on a spinning playground merry-go-round and feeling flung sideways

A prediction-first worksheet — no answer key.

zero prep · no login · any projector

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