Aparticle moves outward along a spiral. its trajectory is given by r = a0 where a is a constant, a = (1/r) m/rad. θ increases in time according to t2/2. where α is a constant (a) sketch the motion, and indicate the approximate velocity and acceleration at a few points (b) show that the radial acceleration is zero when θ = 1/y2 rad. (c) at what angles do the radial and tangential accelerations have equal mag nitula: ?