1. The problem statement, all variables and given/known data An aeroplane loops the loop in a vertical circle of radius 200 m, with a speed of 40 m s^-1 at the top of the loop. The pilot has a mass of 80 kg. What is the tention in the strap holding him into his seat when he is at the top of the loop? Answer: 160 N. 2. Relevant equations A-Level Physics, chapter 6 formulas: w = Angle / t T = 2Pi / w v = wr a = w^2 * r a = v^2 / r 3. The attempt at a solution r = 200 m v / u ? = 40 m s^-1 m = 80 kg Attempt 1. 1/2 mv^2 = mgr -> 64 000 = 160 000. Wrong. Attempt 2. F = ma -> a = w^2 * r -> v = wr -> 40 = w*200 -> w = 0.2 rad s -> a = 0.2^2 * 200 = 8 -> F = 80*8 = 640 N. Wrong. Thank you in advance for any suggestions.