1. The problem statement, all variables and given/known data I have chosen my axis as you can see on the picture. To the left, it is the positive 'r'-axis, up is the positive 'y'-axis. I have to calculate the angular speed. My solution is correct, but i'm getting into trouble at the end. I have to take the roots of the last equation to become the angular speed. Because my acceleration 'ar' is positive, I become a negatif number so I can't take the root. What am I doing wrong? 2. Relevant equations 3. The attempt at a solution Thank you!