Time period $=2 \pi \sqrt{\frac{1}{g}}$
$T \propto \sqrt{I}$
$\frac{T^{\prime}}{T} \propto \sqrt{\frac{I^{\prime}}{I}}$
$T=T \sqrt{\frac{1+l \propto \Delta \theta}{I}}$
$T=T\left(1+\frac{1}{2} \propto \Delta \theta\right)[\alpha \Delta \theta=0.002]$
$\Delta T=T-T=\frac{1}{2} T \propto \Delta \theta=T \times 0.001$
Time lost in time $t$ is
$\Delta T=\frac{1}{2} \quad t=1 \text { day }=24 \times 3600 \,s =86400 \,s$
$\Delta T=\left(\frac{\Delta T}{T}\right) \times t$
$\Delta T=0.001 \times 86400$
$\Delta T=86.4 \,s$

${y_1} = 8\,\cos\, \omega t;\,{y_2} = 4\,\cos \,\left( {\omega t + \frac{\pi }{2}} \right)$ ;
${y_3} = 2\cos \,\left( {\omega t + \pi } \right);\,{y_4} = \,\cos \,\left( {\omega t + \frac{{3\pi }}{2}} \right)$ ,
are superposed on each other. The resulting amplitude and phase are respectively;

Where $k,k_0,k_1$ and $a$ are all positive