1. The problem statement, all variables and given/known data Collars A and B slide along the fixed right-angle rods and are connected by a cord of length L = 7 m. Determine the acceleration of collar B when y = 2.2 m if collar A is given a constant upward velocity vA = 2.66 m/s. The acceleration of B is positive if to the right, negative if to the left. I have attached an image 2. Relevant equations x2+y2 = l2 3. The attempt at a solution[/b I found the distance x, from the base of the support to B to be 6.64529 m I took the derivative of the Pythagorean to get: 2xx' + 2yy' = 0 Then I took the derivative again: 2x'x' + 2xx" + 2y'2 + 2yy" Solving for x" = -x'2 - y'2 -yy"/x x" = -(-yy'/x)2 - y'2/x x" = -0.9057 But it says it's wrong. Where is my mistake?