| [ QuizWit ] in KIDS 글 쓴 이(By): bbmania ( d:)) 날 짜 (Date): 1995년11월27일(월) 20시45분41초 KST 제 목(Title): re] 찻잔의 찌꺼기 Away from the bottom of the cup, there is a balance between the radial pressure gradient and the centrifugal force of the spinning fluid. However, near the bottom of the cup, viscosity slows the motion and the centrifugal force is not sufficient to balance the radial pressure gradient . Therefore, radial inflows takes place near the bottom of the cup. Because of this inflow, the tea leaves always are observved to cluster near the center at the bottom of the cup if the tea has been stirred.By continuity, the radial inflow in the bottom layer requires upward motion & a slow compensating outward radial flows throughout the remaining portion of the cup. The slow outward flow conserves angular momentum, and by replacing high angular momentum fluid by low angular momentum fluid serves to spin-down the vorticity in the cup far more rapidly than could mere molecular diffusion. ***************************** Hi! Hi! Hi! This has been brought you by d:) ******************************** |