Tuesday, February 05, 2013

Today's lesson came as a bit of a shock

We were studying series circuits, so we made one out of students. The Wimshurst machine played the role of the battery.

The shock? That Isaiah is such a great dancer: that guy can shimmy!

Typically students will shriek with anguish upon the discharge of a millimeter spark from the Wimshurst. Within seconds they ask if they can do it again! The human resistors feel the shock in their wrists, not in their hands. Is that because the wrist is the narrowest point along the path of conduction? I don't know, but it seems reasonable.

While the students settle back into their seats to massage their shocked wrists, I demonstrate the spark-generating power of the Wimshurst machine and am typically able to get a spark to jump several inches. The snap is impressive.

What I don't do is attach metal points to the discharge spheres then offer students automatic A's in the course if they see a spark jump on a subsequent cranking of the machine. Who would ever do such a thing? That's just banana sandwich crazy!

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