=bocosat dy vx-dt vv=dt =-aasinωt 当B点(0，b)t=T/4, Uy0V,=-aw→U=U=-aw 2mv-ma 1 a=-a@2cosoti+ba?sin@tj =-w2(acosωwti+bsinωtj)） =-2r F=ma=-ma2r 目录结束 当B点 (0,b) t = T/4， dy dt vy = = aωsinωt t vx x d d = = bωcosωt vy = 0 vx = aω v = vx = aω mv 2 1 2= maω 2 1 2 2 a = i b j 2 cos t sin t 2 aω ω + ω ω = ( i b j ) 2 ω acosωt + sinωt = ω2 r F = m a = ω2 m r 目录 结束