A wheel of diameter 45.0 cm starts from rest and rotates with a constant angular acceleration of 2.50 rad/s2 . At the instant the wheel has completed its second revolution, compute the radial acceleration of a point on the rim in two ways.
1 Using the relationship aredial=ω2r.
2 From the relationship aredial=v2/r.
The Attempt at a Solution
it says second rotation so θ= 2π*2 = 12.57
θ = ωt + ½ α t2
12.57 = ½ 2.5 t2
ω = ω + α t
ω = 2.5 (3.171)
ω = 7.927
a = 7.9272 * 22.5 = 1413.716694
2 should be the same answer since the equations are equal
why is my answer wrong?