Question

The pressure variation that correspond to pain threshold (i.e., the ear can tolerate in loud sound) is about $30Pa$ . velocity of sound in water is $\sqrt{2}\times {10}^{3}m/s$ . The intensity of sound wave produced in water corresponding to loud sound is

• A. $1W/m^2$
• B. $0.3\times {10}^{-3}W/m^2$
• C. ${10}^{3}W/m^2$
• D. ${10}^{-12}W/m^2$

Answer 1

The correct option is B $0.3\times {10}^{-3}W/m^2$

Given,

$P=30Pa,v=\sqrt{2}\times {10}^{3}m/s,I=?$

Intensity of sound wave ,
$I=\frac{P_0^2}{2\rho v}$
$=\frac{30\times 30}{2\times {10}^3\times \sqrt{2}\times {10}^3}=0.3\times {10}^{-3}W/m^2$