Please Help! Plumb Question. 1. I can't figure this out for the life of me. "A plumb line hangs from the ceiling of a jumbo jet's passenger cabin. When the planes is at rest on the rumway, th plumb line is vertical. As the plane accelerates it is observed that the plumb line makes an angle a C with respect to the vertical. What is the plane's acceleration." I want to say that this involves using the equation (a of x)/(g)+(a of y)= tan (c+90) Am I correct?