Q: If Young’s modulus of the material of a rod is Y and density is ρ then time taken by sound wave to travel l length from bottom is
(a) $\displaystyle l \sqrt{\frac{\rho}{Y}}$
(b) $ \displaystyle l \sqrt{\frac{Y}{\rho}}$
(c) $ \displaystyle \frac{1}{l} \sqrt{\frac{Y}{\rho}}$
(d) $ \displaystyle \frac{1}{l} \sqrt{\frac{\rho}{Y}}$
Ans: (a)