10 n==1.6圈 2丌 (4)a1=a=0.4m O=at=0.8×1=0.8rad/s2 an=r()2=05×082=032m/2 = 2+an2=V0322+0.42=0.5ms 0.32 P=arctan=arctan =38.7° 2006-3-15 0.42006-3-15 10 1.6 2 10 = = π n 圈 (4) 2 a = a = 0.4m/s t 2 ω′ =α t′ = 0.8×1= 0.8rad/s 2 2 2 a = r(ω′) = 0.5×0.8 = 0.32m/s n a r v n a v t a v a ′ v ϕ 2 2 2 2 = + = 0.32 + 0.4 n t a a a 2 = 0.51m/s t n a a ϕ = arctan = = 38.7° 0.4 0.32 arctan