1. The problem statement, all variables and given/known data A wheel of radius R starts from rest and accelerates with a constant angular acceleration α about a fixed axis. At what time t will the centripetal and tangential acceleration of a point on the rim have the same magnitude? 2. Relevant equations acp=r x ω2 at= r x α ω= 2π / T → T=2π/ω 3. The attempt at a solution The problem states that the centripetal and tangential acceleration will have the same magnitude at time t. So I listed the equation for centripetal acceleration and tangential acceleration and thought that I can put them equal to each other since the magnitudes are the same. R x ω2 =R x α I canceled out the R ω2= α Here I thought that since ω equals 2π/T I could substitute it for ω since it has T for period which relates to time(2π/T)2 = α I took the square root of that. 2π/T = √α Solving for T T = 2π/(√α) So would this be the time? The AP Physics Book (3rd Edition by James S. Walker doesn't give me a solution since the problem number is even (only gives for odd).