A rock tied to the end of string swings at a constant angular rate. If you are told that the string can support a total of 210 N of force before breaking, what is the maximum angular velocity the rock can rotate if the rock has a mass of 0.23 kg, and the length of the string is 0.35 m? Give your answer in units of radian per second. Note: Do not include units in your numerical answer, however, else your answer will be incorrectly scored