why work done in circular motion is mathematically equal to 0?

Answer 1

Work is the dot product of a force vector and a velocity vector. In circular motion, the vectors are perpendicular so the dot product is zero. In simpler terms, the force has to be in the same direction as velocity for work to be done.

Answer 2

the work done in circular( and all closed shapes too!!!) motion is zero only if the forces are conservative!!!
Otherwise a biker(cyclist) would make no work on pedals.
For conservative forces the work can be calculated only knowing the start and finish point, so if the motion is periodic the work is zero every time the thing passes for the starting point.

Answer 3

Where in the World did you ever get that idea??

Work is the vector dot product of force times displacement. Work done along a non-linear path has to be computed as a line integral of F∙ds over the path taken.

Only if you're working in a scalar field (in which the force is constant at all points) will a closed-path integral come up to 0. And that happens because any work done by the point against the field is exactly balanced by work done by the field against the point as it moves back to its original position. The net energy 'acquired' by the point is 0, so the work done has to be 0.

HTH

Doug

Answer 4

because going around in a circular means zero displacement or distance with direction

Answer 5

Because the total displacement which takes place is zero.

Answer 6

This is because in physics Work is defined as mass moved through a distance. w=md.

Answer 7

It isn't.

If it were cars would use no fuel as long as they always came home.