
A U-shaped tube contains some liquid. The liquid column in each half of the tube has length
, as shown in the figure I below.
The liquid columns are displaced vertically. The liquid then oscillates in the tube. The liquid levels are displaced from the equilibrium positions as shown in figure II above. The acceleration
of the liquid in the tube is related to the displacement
by the expression

where
is the acceleration of free fall.
The length
of each liquid column is
. Determine the period
of the oscillations.
The oscillations of the liquid in the tube are damped. In any one complete cycle of the oscillations, the amplitude decreases by
of its value at the beginning of the oscillation. Determine the ratio
.