Where would Foucault’s pendulum need to be to turn in a complete circle of 360˚?View keyboard shortcutsEditViewInsertFormatToolsTable

Foucault's pendulum would need to be at the North or South Pole to complete a full 360˚ turn in 24 hours. This is because the Earth's rotation doesn't affect the plane of the pendulum's swing at the poles. As a result, the pendulum appears to rotate 360˚ over the course of a day.

Here are the steps to understand this:

1. Foucault's pendulum is a simple device conceived as an experiment to demonstrate the rotation of the Earth. It consists of a tall pendulum free to oscillate in any vertical plane.

2. The direction along which the pendulum swings rotates over time because of the rotation of the Earth. This is a bit counter-intuitive because we usually think of the pendulum as 'swinging back and forth' in a fixed direction, but that's not the case if you take into account the rotation of the Earth.

3. If you were to set up a Foucault pendulum at the equator, it would keep swinging in the same direction, because at the equator, the Earth's rotation doesn't have any 'sideways' component to 'twist' the plane of the pendulum's swing.

4. As you move towards the poles, the 'twisting' effect of the Earth's rotation becomes more pronounced, and the plane of the pendulum's swing would start to rotate.

5. At the North or South Pole, the plane of the pendulum's swing would make a full 360˚ rotation every 24 hours. This is because the 'twisting' effect of the Earth's rotation is strongest at the poles, and there's no 'forward' or 'backward' component to counteract it.