1. The problem statement, all variables and given/known data No specific question. How would one find the critical angle of a ramp given the mass of the block sliding down it and the mu between ramp and block? It's not a single question but something my teacher explained that i didn't understand. 2. Relevant equations F=(mu)mg F=ma I'm not sure of any more 3. The attempt at a solution I just don't get how to calculate the critical angle. Is there a formula or a way to derive some equations? What i know is i have to get the gravity vector that points down the ramp to exceed friction. But how would i set up that equation?