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# Physics/founcault pendulum

Question
Hi,

In foncault pendulum experiment, the pendulum that is hung is moving due to earth's rotation. Why normal pendulum which is hung with a shorter string is stationary.

It's named after a French physicist Léon Foucault, and is therefore spelled the same as his last name.  A normal pendulum is not free to swing along any axis, but constrained to swing by a simple hinge as the Earth rotates.  A Foucault pendulum is not, and the rotation of the plane in which it swings will depend on the rotation of the Earth.  Basically, the pendulum does not change the direction it swings as much as the Earth changes the direction under it in which it sits.  This effect is well-described (for thoroughness, perhaps not for clarity) in wikipedia, if you want full details of how the rotation depends on lattitude.  http://en.wikipedia.org/wiki/Foucault_pendulum

Physics

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