Physics Demo Number: 077

Approximate Run Time: 10 min

Simple Pendulum on Stand (Show resonance build up)

Demo Description

One may show that rapid pecking forces on the hanging mass produce no oscillation of any magnitude.

However by switching to appropriately-timed small pecks, one may build up a large-amplitude swinging motion of the mass.

 

Scientific Principles

  • Forces and oscillating motion.

  • Resonance build up

Equipment

  • Physics Stand

  • Mass

 

Equipment Location

  • Apparatus lives on [E-1-5]-[E-2-5]

  • Some Parts in Kit (077) on [E-2-5].

Instructions

By using the apparatus in the photo, one can show that short, rapid hits on the hanging mass produce no oscillation.

However by switching to appropriately-timed hits, even if they be very small in magnitude, one may build up a large-amplitude swinging motion of the mass.

An alternative setup is to hang the old cannonball as described in demo(004) , and hit it with rapid jolts from a rubber hammer.

Then one may hit the cannonball with well-timed jolts.
  
Writeup created by David A. Burba
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