1. The problem statement, all variables and given/known data The model airplane in Figure 5.6 has a mass of 0.90 kg and moves at a constant speed on a circle that is parallel to the ground. The path of the airplane and its guideline lie in the same horizontal plane, because the weight of the plane is balanced by the lift generated by its wings. Length is 17 m. and speeds of 19 and 38. The toy plane goes around in a circle that is parallel to the ground, at constant speed. Is the plane in equilibrium? 2. Relevant equations 3. The attempt at a solution I know that having a net force of zero or centripetal force of zero allows to be at equilibrium. The centripetal force is also directed toward the center of the circle and net force is the vector sum of all the force components that point along the radial direction.