# Two simple pendulums A and B are made tooscillate simultaneously and it is found that Acompletes 10 oscillations in 20 sec and Bcompletes 8 oscillations in 10 sec. The ratio ofthe lengths of A and B will be ?

Khimraj
3007 Points
4 years ago
Time period in SHM is given by,
T = 2$\prod \sqrt{l/g}$
So l $\propto$ T2
Time period of A, Ta = 20/10 = 2 sec.
Time period of B, Tb = 10/8 =  5/4 sec.
Ration of length La/Lb = (Ta/Tb)2 = (8/5)2 = 64/25