Coulomb's law (electrostatic bell, electrostatic drum, electrostatic floating paper)

(1) Electrostatic Bell: Activate the high-voltage electrostatic generator to immediately build a strong electric field, using electrostatic attraction to make the specially designed bell hammer strike the bell without contact, producing a crisp bell sound and intuitively demonstrating Coulomb's Law, which states that the force between charges is inversely proportional to the square of the distance. (2) Electrostatic drum: The exhibit cleverly combines electrostatic mechanics and classical physics principles. The display cabinet is equipped with two pointed metal conductors, which generate "electric wind" by discharging the tips of the double pointed conductors through high-voltage static electricity, driving the central drum to rotate without contact. (3) Electrostatic floating paper: Press the button, and the paper will immediately float up, demonstrating the accumulation of charges and the electrostatic repulsion overcoming the gravity of the paper to achieve suspension, intuitively interpreting Coulomb's law.

The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.