Coulomb's Law Concept

Demonstrations in Coulomb's Law

Wooden rod with white Teflon tube on one end and dark glass tube on the other, suspended horizontally by strings from a metal stand. On the table: orange balloon, gray felt cloth, and white charging rod.

Electrostatic Compass

Demonstrates that two types of electric charge exist and that like charges repel while opposite charges attract. The suspended rod with known positive (glass) and negative (Teflon) reference charges acts …
Two small pith balls hanging from threads on an L-shaped metal arm mounted on a scissor jack. In front: a glass rod, white Teflon rod, black cat's fur, and white silk cloth.

Pith Balls

Two pith balls on threads demonstrate that like charges repel and opposite charges attract. Charge the balls with glass (positive) and Teflon (negative) rods to show both cases. Use shadow …
Hands rubbing a green water balloon with black felt cloth while a blue balloon hangs from a string nearby

Charged Balloons

Suspended balloons are charged by rubbing with felt (negative) or against a Teflon disk (positive) to demonstrate electrostatic attraction and repulsion. The separation angle provides a qualitative measure of the …
Torsion balance with suspended metal sphere on rod, laser module on wooden beam, water-filled glass damping cell clamped to ring stand at left, green laser spot on blackboard between two meter sticks
Safety

Coulomb's Law

Quantitatively demonstrates Coulomb's Law using a torsion balance and laser readout. Students verify the inverse-square distance dependence and linear charge dependence by observing laser spot displacement on the blackboard as …