1. The problem statement, all variables and given/known data I'm not from an English speaking country. I hope that you'll understend my question. Cone made of steel is rotating on the wooden desk. Radius of cone is 4 cm, height is 10 cm. Density of steel is 7,8*10^3 kg/m^3. Angular velocity of cone is 3.14 rad/s. Find the force of friction. Cone is rolling without sliding. 2. Relevant equations 3. The attempt at a solution I tried to solve this but i don't know where to start. I got mass from density and volume. I know that i have two forces - one that keeps cone rolling and the friction that slows it down. My problem is that I don't know what to do because the cone is rolling arround an axis which doesn't go through it's center of mass. If someone could help me with applying Newton's second law on this I would be very grateful. If there is something that you don't understand please ask i will answer. It is very important that i solve this one. Please help.