| MadSci Network: Physics |
No, centripetal force does not do work on an object,
since the force always acts perpendicular to the motion
of the object. Given a constant (magnitude) central
force, which causes an object to revolve in a fixed
circle, there is no energy exchange, and thus no work.
Take the Earth in its orbit, for example. Its kinetic
and potential energies do not change, even though its
momentum is continually changing (in direction).
While force is F=dP/dt (change in momentum with change
in time), work is F*dr, the dot product of the force
vector and the position change vector (i.e. the force
times the perpendicular component of the position change).
-Aaron
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