. A rock of mass 0.5 kg is launched straight up. A constant upward force of 405 N acted on the rock while it moved 25 cm upward starting from rest. Ignore air resistance. a. Find the launce speed using the work-energy theorem [use g = 10 m/s2). b. Using energy ideas, find the maximum height above the launch point (25 cm) the rock will reach.​

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,?