1. The problem statement, all variables and given/known data A ball swings in a vertical circle at the end of a rope 1.50 m long. When the ball is 36.9° past the lowest point on its way up, its total acceleration is (-22.5i, 20.2j) m/s2. At that instant, (a) determine the magnitude of its radial acceleration, and (b) determine the speed and velocity of the ball. 2. Relevant equations a = v2/r 3. The attempt at a solution Centripetal acceleration resolved into two components, in x direction, -22.5 and y direction, 20.2. I would think that in order to get the net acceleration, just (22.5^2 + 20.2^2)^0.5. However, this yielded an incorrect solution. Why doesn't this work and what is the correct approach?