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Funnel Fun

  • A funnel
  • A pingpong ball
  • Procedure: Try to blow the ping pong ball out of the funnel with the funnel pointing up or down. As long as you are blowing, the ball will stay in the funnel.

    Explanation: The funnel acts as a diffuser, with the air slowing down and the pressure increasing, until it exits at atmospheric pressure. This means that the pressure on the downstream side of the ball is always greater than the pressure on the upstream side, pushing the ball back toward the mouth of the funnel. As long as that pressure difference is large enough to support the weight of the ball, the ball will remain floating in the funnel.
