The Foucault pendulum is a device used to demonstrate the rotation of the Earth.
modelling clay, skewers, marbles, rubber ball, thread, plate, clay dish, sand, needle, Make four small balls from modelling clay., Connect the balls of modelling clay with the skewers so that they form a tetrahedron., The pendulum will be suspended from the apex., Insert a threaded needle through the apex of the tetrahedron., Then insert the needle through the rubber ball. This will be the pendulum., Fill a clay dish with marbles. , Place the plate on the marbles, then pour sand into it., Position the tetrahedron on the plate so that its apex is above the plate’s centre., Set the pendulum swinging., While the pendulum is swinging, move the plate around carefully., What do you think?, If the pendulum were to swing forever, what would happen to the lines traced in the sand? Why?, Explanation, The movement of the pendulum in the vertical plane is traced by the line it draws in the sand with the needle., The plane in which the pendulum moves changes with time as a consequence of the Earth’s rotation., This is modelled with the rotation of the plate., Here is what you need