How can a pendulum demonstrate the rotation of Earth?
In 1851, French physicist Jean-Bernard-Leon Foucault (1819–1868) proved that Earth rotates on its axis through a demonstration with a pendulum. A pendulum consists of a free-swinging cord set at a fixed point with a weight hanging from it. A pendulum swings at a constant rate and direction if there is no force moving against it. Foucault hung a pendulum from a high ceiling and noted that the path of the pendulum’s swing slowing changed its direction of swing. Since there was no force acting on the pendulum, he concluded that Earth had to be rotating beneath it. In this experiment you will make a simple Foucault pendulum. When a pendulum is moving freely in air, the air resistance causes the pendulum to slow down and eventually stop. A…
