LESSON REVIEW # 7B.....November 4, 2000..."Swinging"

                              Cleophas Mike McAlpin......Tutor

   "The Foucault Pendulum is no longer a mystery to us. Let's dance!"                                    

  A crowd was gathered in the lobby of the Griffith Park Observatory. All eyes were on a giant ball that swung from the end of a steel wire of 40 feet. The steel ball swept from one side to the other, knocking over tiny fingers as it swung. All eyes followed the oscillations of the Foucault pendulum as it made one oscillation in 7.0 seconds. It marked the rotation of the earth and knocked over "fingers" as it swung.

It was not long after the 11 students and  2 tutors of a "Free Tutoring Service" arrived in the lobby of the Observatory that all eyes fell upon them. The students took out a watch, a Scientific Calculator and quickly went to work on dissecting the Physics project that was concocted by Leon Foucault in 1851.

Of course, very few onlookers knew as much about the giant Foucault pendulum as the students. The students had investigated the formula T = 2p Ö L/G  , and knew that those 7.0 seconds had to be placed in the formula instead of the "T". They knew that 40 feet had to be placed in the formula instead of the "L". They knew that finding the "G" was just a matter of simple Algebra. The acceleration due to gravity should be, of course, 32.2 feet/second/second, or 9.8 meters/second/second.

A Beautiful Nov. 4, 2000 Reading the Sun Dial in back? No problem. Future scientists stand here at the base of scientists of the past( Galileo, Kepler, etc.)

T = 2pÖ L/G  (Also see Lesson Review 3B)

The students took ten "back and forth motions" of the giant pendulum. They averaged the swings and came up with one oscillation (to and fro) in a time of 7.0 seconds. The time of one oscillation was all that was necessary to calculate the acceleration due to gravity, "G",  at this location high above the City of Los Angeles. 

An Algebra lesson followed the experiment. It dealt with finding one unknown in an equation when two are given. We took the equation above and squared each side to get rid of the radical. Then we input “L” and “T” and solved for “G”. It was 9.8 meters/second², just as Foucault had predicted back in 1851!  

By the way, if you need the frequency of oscillations, simply divide "T" into "1" or f = 1/T;   Frequency in this case = 0.142 cycles/second

The students should receive extra-credit at their respective Middle and High Schools. They did a very good job. It did not stop at the Foucault pendulum, it continued to the Periodic Table of the Elements. www.webelements.com 

James, Jarrell, Jeremiah and Cleasena reviewed the giant Table with Sheena, Joshua and Margaret. The took turns at describing each group of elements on the Table. They pointed out the Spectral Lines of some elements and told of electron configurations, physical characteristics and combining properties of some of the elements. Again, a crowd of onlookers gathered to listen to the lectures given by the students of "A Free Tutoring Service."

The giant "Tesla Coil" was no mystery to the students, either. They watched as a guide described the giant "lightning generator" and seemed a bit bored when the Noble Gases (Argon, Krypton, Xenon, Neon, Radon), in the "tesla coil letters" glowed with the colors of those inert gases (when their atoms were excited by the lightning machine). The students are very knowledgeable about all of the elements on the Periodic Table of the Elements. They also strengthened their knowledge of step-up transformers, power generation, and electrical current flow from our Hoover Dam excursions of the past. 

I explained several exhibits to Margaret, Jarrett and Joshua. Joshua and Jarrett are now knowledgeable about the Hubble Telescope on its solar panels. They are knowledgeable about galaxies, sunspots, Martian rocks, moons of Jupiter and space debris.

It was then on to Universal City Walk for a little relaxation and fun!