A 2.4 kg object attached to a horizontal string moves with constant speed in a circle of radius R on a frictionless horizontal surface. The kinetic energy of the object is 95 J and the tension in the string is 315 N. Find R.

Answer 1

string tension = m V^2/R
= 2*(K.E.)/R = 315 N

Solve for R

Answer 2

I have no idea