The bob of a simple pendulum executes simple harmonic motion in water with a period t, while the period of oscillation of the bob is t0 in air. Neglecting frictional force of water and given that the density of the bob is (43)1000kg/m3. What relationship between t and t0 is true?
t=2t0
When immersed in water, effective value of g is g′=(ρ−ρwρ)g where ρ is density of object and ρw is that of water.
Now, tt0=2π√lg′2π√lg=√gg′=√ρρ−ρw
Substituting values, we get t=2t0