1. The problem statement, all variables and given/known data Write the vector expression for the acceleration a of the mass center G of the simple pendulum in both n-t and x-y coordinates for the instant when θ = 66° if θ'= 2.22 rad/sec and θ"= 4.475 rad/sec2 I have attached an image of the question. 2. Relevant equations an = v2/r = rθ2 = vθ' at = v' = rθ' 3. The attempt at a solution I've managed to calculate en and et correctly at = (4.2 ft)(4.475 rad/sec2) = 18.795 ft/sec2 at = 18.795ft/sec2 For an I calculated velocity first: v = rθ' = (4.2ft)(2.22 rad/sec) v = 9.324 ft/sec Hence an = (9.324 ft/sec)(2.22 rad/sec) an = 20.69928 ft/sec2 Unfortunately, I'm now having difficulty with finding the velocity in terms of i and j. I had thought that I could use geometry to do it: atcos(90-66) = -17.77 i atsin(90-66) = 7.644 j But the system says it's wrong. Help is greatly appreciated.