A child A is swinging from a swing that is attached to a trolley that is free to move along a fixed rail. Letting L = 3.4 m, if at a given instant aB = 3.3 m/s2 . theta = 23 degrees, theta dot = 0.45 rad/s and theta double dot = -0.2 rad/s2. Determine the magnitude of the acceleration of the child relative to the rail at that instant. Give answer to four significant figures.