In a certain observation of experiment with simple pendulum we get l=23.2 cm, r=1.32 cm and time taken for 20 oscillations was 20.0 sec. Taking π2=10, find the value of g in proper significant figures.

Equivalent length of pendulum,L=23.2 cm+1.32 cm=24.52 cm=24.5 cm (according to addition rule of significant figures)Time period, T=20.020=1.00 s. Time period has 3 significant figuresg=4π2lT2=4×10×24.5×10-2(1.00)2=9.80 m/s2