Hi! I am reviewing for the Physics GRE and am perplexed by this problem: 1. The problem statement, all variables and given/known data A ball swings in a vertical circle at the end of a rope 1.5m long. When the ball is 36.9 degrees past the lowest point on its way up, its total acceleration is (-22.5, 20.1)m/s^2. At this instant (a) sketch a vector diagram showing the components of its acceleration, (b) determine the magnitude of its radial acceleration, and (c) determine the speed and velocity of the ball. 2. Relevant equations a_c = v^2/R sin(angle) = opposite/hyp. cos(angle) = adjacent/hyp. 3. The attempt at a solution See attached images. I agree with the solutions I have attached for part (a), but not for (b) or (c). Especially how the solution manual determines the components of the radial acceleration in part (b) and direction of velocity in part (c).