Two spherical bob of masses mA and mB are hung vertically from two strings of lengths IA and lB respectively. They are executing SHM with frequencies fA and fB such that fA=2fB.Then :

A
$l_{A} = \frac{l_{B}}{4}$
B
$l_{A} = 4 l_{B}$
C
$l_{A} = 2 l_{B} and m_{A} = 2 m_{B}$
D
$l_{A} = \frac{l_{B}}{2} and m_{A} = \frac{m_{B}}{2}$

Solution:

$f = \frac{1}{2 π} \sqrt{\frac{g}{l}} \Rightarrow f \propto \frac{1}{\sqrt{l}} \Rightarrow \frac{f_{A}}{f_{B}} = \sqrt{\frac{l_{B}}{l_{A}}} \Rightarrow \frac{2 f_{B}}{f_{B}} = \sqrt{\frac{l_{B}}{l_{A}}} \Rightarrow l_{A} = \frac{l_{B}}{4}$

Two spherical bob of masses m_A and m_B are hung vertically from two strings of lengths I_A and l_B respectively. They are executing SHM with frequencies f_A and f_B such that $f_{A} = 2 f_{B}$ .Then :

Solution:

Related content