A U-shaped glass tube with a uniform cross-sectional area, $A$, is partly filled with fluid of density $\rho$. Increased pressure is applied to on:
of the arms resulting in a differcnce in eleva. tion of $L$ between the two arms of the tube as shown in the figure. The increased pressure is then removed, and the fluid oscillates in the tube. Determine the period of the oscillations of the fluid column. (You have to determine what the known quantities are.)