Normal time period \(T=2 \pi \sqrt{\frac{l}{g}}\)
When immersed in a liquid. It experiences an upthrust.
Upthrust \(=\frac{\rho}{4} \times\) volume \(g\)
Upward acceleration \(=\) Upward force \(/\) mass of ball \(=\frac{g}{4}\)
\(T^{\prime}=2 \pi \sqrt{\frac{I}{g_{e f f}}}\)
\(g_{\text {eff }}=g-\frac{g}{4}=\frac{3}{4} g\)
\(T^{\prime}=2 \pi=\sqrt{\frac{1}{3 g} \times 4}=\frac{2 T}{\sqrt{3}}\)
(પાણીની ઘનતા $=10^3\, kg/m^3$ આપેલ છે.)