If a person travels up I-75 North for 80 miles, and then realizes he missed an exit with Chick-fil-a, travels 5 miles south down I-75, and then travels 40 more miles up I-75 North to get to his destination, what is the distance the person travels what is the displace of the person?

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,?