1. The problem statement, all variables and given/known data It seems simple, doesn't it? A bead starts from (0,1/2) and simply slides down the parabola y=(1/2)(x-1)2 under gravity. The problem is to get its position rel. to origin in terms of time, ie. r = [x(t),y(t)]. Anyone into this? 2. Relevant equations y' = x-1 = tan A where A is angle tangential veloc. (v) (and tang. accel.(a)) makes with x axis. a = -g sin A . 3. The attempt at a solution For starters, can I say that sin A = -(x-1)/sqr(1+(x-1)^2) ?