Half wood and half metal physical pendulum with suspension points at both ends.

What it shows:

The period of a physical pendulum is measured and compared to theory:



where I is the rotational inertia, g is the acceleration due to gravity, and x is the distance...

A replica of Franklin's Thunder House demonstating the efficacy of his invention—the lightning rod. The class will get a charge out of this one.

A lens immersed in a fish tank of water seems to lose its refractive powers to focus light.

What it shows:

A lens seems to lose its ability to focus when immersed in water. This models the inability of us landlubbers to see clearly under water.

What it shows:

Gamma rays are electromagnetic radiations which we detect as quanta of energy or photons. When the radioactive source is confined so that it acts as a point source, the diminution in the number of photons incident on a given area is such that the intensity is inversely proportional to the square of its distance from the source.

How it works:

A Co-60 source (1.173 and 1.332 MeV gammas) radiates isotropically. A Geiger-Müller counter is used to detect the radiation intensity at distances of 2, 3, and 4 meters. The...