Lag1989 task №1.45

A point moves along a circle, so that the time dependence of the path described by the equation S = Bt + Ct²; where B = -2 m / s; C = 2 m / s². After t₁ = 1 s after the start of movement of the acceleration terms an = 0,5 m / s2. Find time τ, where the modules are normal and tangential acceleration are equal.