(a) In class, I claimed that circular motion defined by r(t) = Acos(wt)i + Asin(wt)j satisfies the equation ma(t) = qu(t) x B as long as w = qB/m. Verify (through direct substitution) that this is indeed the case for the B-field orientation and coordinate vectors i, j as defined in class. (b) Show that qB/m has units of 1/time (as it must!). (c) How long does it take a proton to complete a circular orbit perpendicular to a uniform magnetic field with strength B = 2.4 x 10-4 T? (d) What is that magnetic field strength B in Gauss