A U tube of uniform bore of cross-sectional area A has been set up vertically with open ends facing up. Now m gm of a liquid of density d is poured into it. The column of liquid in this tube will oscillate with a period T such that
If the level of liquid is depressed by y cm on one side,
then the level of liquid in column P is 2y cm higher than B as shown.
The weight of extra liquid on the side P = 2Aydg .
This becomes the restoring force on mass M.
∴Restoring acceleration=−2AydgM
This relation satisfies the condition of SHM i.e. a ∞−y
Hence time period T = 2π√DisplacementntAcceleration
= 2π√y2AydgM⇒T=2π√M2Adg