Question

The minimum distance of a reflector to hear the echo of monosyllabic sound is (speed of sound is $330m{s}^{-1}$ )

• A. 16.5 m
• B. 33 m
• C. 165 m
• D. 330m

Answer 1

Answer: (B)

Monosyllabic sound reaches the listener after reflection in $\frac{1}{5}s$ . Distance between source and listener is $d=v\left(\frac{t}{2}\right)=330\times \left(\frac{1}{2}\times \frac{1}{5}\right)$ $d=330\times \left(\frac{1}{10}\right)=33m$