Great Balls and Fire! Smashing Steel Spheres with Video

June 13, 2010

Tami O'Connor, Educational Innovationsby:  Tami O’Connor

When two 1-pound, 2-inch diameter, chrome steel spheres are smashed together, enough heat is generated at the point of contact to burn a hole in ordinary paper!  This dramatic demonstration has been a favorite of students in every grade for as long as I have been teaching!

Smashing Steel Sphere Demo KitThere are a few considerations when allowing students (especially younger ones) to conduct this activity on their own…  First, the spheres are pretty heavy, so if they were either dropped on a foot or onto a nice tile floor, the result would not be good.  Also, be sure that the only thing between the spheres is paper or aluminum foil.  Fingers caught between the colliding spheres would not  be happy.  Finally, all participants should wear safety glasses, as it is not unusual for a small piece of paper to fly off after the spheres collide.

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2 Comments | College level, Elementary level, energy, experiments, High School level, Middle School level, Physics | Tagged: , , , , , , , , , | Permalink
Posted by Tami O'Connor

Atomic Penny Vaporizer

March 25, 2010

Marty Sagendorfby: Martin Sagendorf

Imagine students’ amazement when they actually see sunlight melt a penny with the Atomic Penny Vaporizer!  This demonstration clearly illustrates the vast amount of energy illuminating the Earth’s surface.  In rough numbers: 70% of the Sun’s incident energy on our outer atmosphere is reflected back into space – only about 30% actually gets to the Earth’s surface.  But, as we experience, this is still a substantial quantity of energy.

Fortunately, this energy (I. R. – Visible – U. V.) is rather uniformly distributed over the Earth’s surface –  thus its overall intensity is such that we have a habitable environment.  However, as we all know, we can concentrate some ‘area’ of this energy to increase the ‘energy per area’ (a measure of this is the temperature of the area of concentrated energy).  A common magnifying lens (2-4 in. diameter) will concentrate sufficient energy to burn paper or other objects with a low flash point. Read the rest of this entry »

2 Comments | College level, energy, experiments, High School level, Middle School level, Physics | Tagged: , , , , , , , , | Permalink
Posted by Tami O'Connor

The Amazing Drinking Bird

December 1, 2009

Tami O'Connor, Educational Innovationsby Tami O’Connor

Invented in 1945 by Miles Sullivan, the “drinking bird” has been a favorite of science teachers in every classroom from kindergarten through college. This amazing device is made of two glass bulbs (one representing the head and the other representing the body) joined by a glass tube (representing the neck).  Between the two bulbs, attached to the glass tube, is a metal fulcrum upon which the bird pivots.  The air has been removed from this closed device, and the bottom ball is filled with a colored liquid that has a high vapor pressure (methylene chloride). The rest of the bird’s body and head is filled with the vapor form of methylene chloride.

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1 Comment | Chemistry, College level, Elementary level, energy, experiments, High School level, Middle School level, Physics | Tagged: , , , , , , | Permalink
Posted by Tami O'Connor

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