Define reflection of sound?

The diagram shows a series of volcanic island and a hot spot determine the direction of movement of the tectonic plate that for the island

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,?

Which describes an object in projectile motion? check all that apply. a.gravity acts to pull the object downb. the object moves in a straight path. c.the forward velocity of the object is 0 m/s. d.the object’s inertia carries it forward. e.the path of the object is curved.