What is the coordinates of the point that is 1/5 of the way from A(-7,-4) to B(3,6)?

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,?

An object in mechanical equilibrium is an object

What are the dimensions of the cross section that passes through the points a, f, g, and d?