Hi! I got the task to determine the moment of inertia of a hollow cylinder, however it's not about just measuring the mass and the inner and outer radius and putting it into the right formula, instead I should roll it down an inclined plane. 1. The problem statement, all variables and given/known data I'm only allowed to use the following tools: An inclined plane Ruler and measuring-tape Vernier caliper Stopwatch A hollow cynlinder The problem states that the friction can be neglected and that the kinetic energy of the cynlinder will be the sum of it's translational and rotationan energy. 2. Relevant equations Translational energy: Et = 1/2 * m v2 Rotational energy: Er = 1/2 * I ω2 Potential energy Ep = mhg 3. The attempt at a solution My idea was to measure a short distance infront of the inclined plane, roll the cylinder down and use the stopwatch to determine the cylinders approximate velocity when leaving the plane. The angular velocity could then be calculated with the help of a measurment of the cylinders circumfence. Then, using the law of conservation of energy we get: I = 2m (hg - v2)/ ω2 The problem is that this expression (just as the others I tried to derive) contains the mass of the cylinder... Do you have any suggestion on how the measurment and the calculations should be done? Thank you!