This is not homework. Suppose I am rotating a ball on a string (m=1, r = .2, v = 10 m/s)
Fc = (m) v2/r = 500 N*m
If I reduce the length of the string to .1, v becomes 20, so
Fc = 4000 N*m
what is the work I have done, what kind of integration do I need,
does the energy spent depend on the speed/time I use to pull the string?
Thanks for your help