Which is an example of a scientist using a conceptual model to describe a volcano?
a. the scientist calculates the amount of lava that comes out a volcano.
b. the scientist thinks of the volcano as an exploding fire hydrant.
c. the scientist uses a computer to predict whether the volcano will erupt
d. the scientist uses mud and vinegar to make a model of the volcano
e. im not sure

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,?