切向加速度
a = dv/dt = d(ωr)/dt = r dω/dt = 0.3 * 0.5 = 0.15 [m/s^2]
法向加速度
A = ω^2r
(dω/dt)t^2/2 = θ
ω = t dω/dt
ω^2 = t^2 * (dω/dt)^2 = 2θ dω/dt
A = 2θr dω/dt = 2 * 240/180*π * 0.3 * 0.5 = 0.4π = 1.256 [m/s^2]