Physics Demo Number: 033

Approximate

Run Time: 5min
Inertia Shown By Snatching Tablecloth Out from Under Tableware

Demo Description

Place a plate and glass of water on a slick piece of cloth on the lecture table. Now jerk the cloth clear of the lecture table without disturbing the place setting.

 

Scientific Principles

  • Newton's First Law and Inertia

Equipment

  • Heavy Plate

  • Drinking Glass

  • Silverware

  • Smooth Cloth

 

Equipment Location

  • Kit (033) on [E-3-4]

Instructions

Practice is highly recommended for this demo.

One needs to locate the place setting near an end of the lecture table, and ensure that enough cloth is hanging down off the table to enable grasping the cloth firmly with both hands.

Then ensure that both hands are

  1. at least at table level in their vertical positioning, and

  2. close to the end of the table in their horizontal positioning.

    One now must execute a very sharp impulse downwards with the hands. 

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One may do an alternate demo of this idea by replacing the table with the bottom one of the two pictured Pasco Carts, the table cloth and place-setting by a person- and- the top cart.

One then jerks the table out from under the table cloth and person.

                                                                 Table and Tablecloth Carts

Writeup created by David A. Burba
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