Lesson Plan
Science and Mathematics Initiative for Learning Enhancement (SMILE)

Smile: Measuring the Gravitational Constant, G

For Teachers 9th - 10th
A demonstration/lab idea for determining the numerical value of the universal gravitation constant using a torsion balance.
Handout
Wikimedia

Wikipedia: Henry Cavendish

For Students 9th - 10th
Wikipedia offers biographical information on the British scientist Henry Cavendish (1731-1810), credited with having discovered hydrogen, which he described as "inflammable air."
Interactive
National High Magnetic Field Laboratory

Magnet Academy: Torsion Balance

For Students 9th - 10th
Experiment with the torsion balance and see what happens first by giving the rod a charge, and then by moving the charged rod closer to the outer metal sphere of the instrument. Observe what happens to the needle as the charge increases.
Interactive
National High Magnetic Field Laboratory

Magnet Academy: Torsion Balance 1785

For Students 9th - 10th
Read about Charles Augustin de Coulomb, who didn't invent the torsion balance, but was the first to discover it could be used to measure electrical charge- the first device capable of such a feat.
Unit Plan
National High Magnetic Field Laboratory

Magnet Academy: Charles Augustin De Coulomb

For Students 9th - 10th
Charles-Augustin de Coulomb invented a device, dubbed the torsion balance, that allowed him to measure very small charges and experimentally estimate the force of attraction or repulsion between two charged bodies. The data he obtained...
Unit Plan
Physics Classroom

The Physics Classroom: Cavendish and the Value of G

For Students 9th - 10th
A short description of how Cavendish measured the value of G - the universal gravitation constant and supported Newton's theory. Illustrated.