The periodic time of a simple pendulum, (the simple pendulum with its bob is in air) is T. But if the bob of the simple pendulum is completely immersed in a non viscous liquid, whose density is 1 20 times the density of material of the bob, then its new period will be

Step-by-step solution

The time period of a simple pendulum in air is given by T = 2 L g . When the bob is immersed in a liquid, the effective acceleration due to gravity g' becomes: g' = g (1 - ) where is the density of the liquid and is the density of the material of the bob. Given that = 20 , we have: g' = g (1 - 1 20 ) = 19g 20 The new time period T' is: T' = 2 L g' = 2 L 19g 20 = 2 L g 20 19 T' = 20 19 T Answer: 20 19 T