NEET2005PhysicsMechanical Properties of FluidsActual
A given shaped glass tube having uniform cross section is filled with water and is mounted on a rotatable shaft as shown in figure. If the tube is rotated with a constant angular velocity when
Options
- Awater levels in both sections A and B go up
- Bwater level in section A goes up and that in B comes down
- Cwater level in section A comes down and that in B it goes up
- Dwater levels remain same in both sections.
Correct answer
A. water levels in both sections A and B go up
Step-by-step solution
Due to rotation about the axis O O^ , a force is acting on the liquid column A B outwards, pushing up the liquid column on the right. This centrifugal force acting on the small element d x of area of cross-section d x , distant x from the axis is d m ^2 x=A d x ^2 x The total force due to column of length L(=A B) is ₀^L A ^2 x d x=A ^2 L^2 2 Pressure at B= atmospheric pressure + h₁ g+ A ^2 A L^2 2 Pressure at B due to liquid column on the right hand side = atmospheric pressure +h₂ g Net pressure due to the left han