Answer:
work done by tension force on the twirled stone must be ZERO always
Explanation:
As we know that work done by a force on an object is given as
[tex]W = F.d[/tex]
[tex]W = Fdcos\theta[/tex]
here we know that
[tex]\theta[/tex] = angle between force and displacement
now we know that tension in the string and displacement of the object is always perpendicular to each other when the rock is twirled in circular path.
so we can say for this motion of the stone
[tex]cos\theta = 0[/tex]
so work done by tension force on the twirled stone must be ZERO always