Question

An echo is heard on a day when temperature is about ${44}^0$C. When will the echo be heard if the temperature falls to ${80}^0$C?

• A. Sooner
• B. Later
• C. At the same time
• D. No echo will be heard

Answer 1

The correct option is A Sooner

Time, after which an echo is heard is given by $t=\frac{Distance}{Speedofsoundinair}$
Therefore, since speed of sound in air increases with the increase in temperature, so the time after which echo will be heard decreases. Hence, echo will be heard, sooner than the echo heard when temperature near ${44}^{0}C$