"Dr. Slick" wrote:
wrote in message ...
Actually, you've done 2*pi*radius*force work. Moving one circumference
times the force.
Actually, thats 2*pi*radius*force*moment arm. Right.
In my example, I intended the 'radius' to be the radius at which the
force was applied so the 'moment arm' was already accounted for. When
the radius is the radius at which the force is applied, 2*pi*radius
is the distance through which the force has acted after one revolution
so the expression is the same as the common force*distance used for
linear work. More generally, it does not matter what the shape of the
path is; the work is always the force times the distance along the path.
....Keith