1. The problem statement, all variables and given/known data An airplane is flying in a circle at a speed of 480km/h. It wings are tilted at 40 degrees to the horizontal. What is the radius of the circle in which the plane is flying? Assume that the required for is entirely provided by "aerodynamic life" that is perpendicular to the wings. 2. Relevant equations f=ma a=v^2/r 3. The attempt at a solution I tried this and got what seems like a reasonable answer but the books answer guide differs, what am I missing here? for the X direction i get N cos(40) = mv^2/r for the Y direction I get N sin(40) - mg = 0 so.... N = mg/sin(40) Substituting back and solving for r r = (v^2 tan(40))/g What am I missing?