A girl with a mass of 27 kg is playing on a swing. There are three main forces acting on her at any time: gravity, force due to centripetal acceleration, and the tension in the swing's chain (ignore the effects of air resistance). At the instant shown in the image below, she is at the bottom of the swing and is traveling at a constant speed of 3 m/s. What is the tension in the swing's chain at this time? (Recall that g = 9.8 m/s^2)

During the experiment if you could triple the breakaway magnetic force with all other quantities left unchanged, what is the new value for the critical velocity if it was v0 (initial velocity), initially? (b) now if you halved the radius with all other quantities left unchanged, what is the new critical velocity if it was v0 (initial velocity), initially? (c) if during the experiment, critical velocity quadrupled with all other quantities left unchanged, what is the new breakaway force if its magnitude was initially f0,?