BITSAT2021PhysicsMechanical Properties of FluidsActual
A U - shaped tube contains a liquid of density rho and it is rotated about the left dotted line as shown in the figure. Find the difference in the levels of liquid column.
Options
- A² ~L ² 2 g
- B² L² 2 2 g
- C2 ² ~L ² g
- D2 2 ² ~L ² g
Correct answer
A. ² ~L ² 2 g
Step-by-step solution
Weight of liquid of height ( H = d ² 4 H g ) (i) Let us consider a mass dm situated at a distance (x ) from (A ) as shown in the figure. The centripetal force required for the mass to rotate (=( dm ) ² ) ( ) The total centripetal force required for the mass of length (L ) to rotate (= ₀¹ ( x d ² 4 ) xdx ( x ² )= d ² 4 ² 1² 2 ) (ii) This centripetal force required is provided by the weight of liquid of height 'H' From (i) and (ii) ( aligned & d ² 4 H g = d ² 4 ² 1² 2 & H = ² l ² 2 ~g aligned )