A spring is hung from the ceiling. When a 0.450-kg block is attached to the free end of the spring and released from rest, the block drops 5.0 cm before momentarily coming to rest, after which it moves back upward. What is the spring constant of the spring?

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,?