1. The problem statement, all variables and given/known data I have to write a C# program for an assignment for school. Programming is not a problem, but physics is :P So I am kindly asking you guys for helping me out with this.. Sorry for my bad english, I'm not a native speaker. A glider pilot starts a back-loop with a plane, flying horizontally at a speed of 60 m/s. Maneuver is carried out so that he pulls the stick back and holds it in the same position througout the whole loop. The initial centripetal acceleration is 30 m/s2 in the direction vertically upwards. 2. Relevant equations I must calculate the position, velocity and acceleration of the aircraft as a function of time during the interval from the beginning implementation of acrobatics to the time in which the aircraft at a constant acceleration is outlining a full circle. Does the aircraft come back to the original/initial position? The origin is placed at the point at which the airplane moves from the horizontal position of the ribbon/loop. I really hope I translated it so you can understand. 3. The attempt at a solution I'm not really good at physics so I don't even know how to start :/ Acceleration due to gravity is 9.8 m/s2 Air resistance can be neglected, so that the only force acting on the plane is the force of gravity and the lift force, which is perpendicular to the direction of the current speed of the airplane. Surrounding air is stationary relative to Earth and a plane (throughout the maneuver) doesn't rotate around its horizontal or vertical axis.