Question

To hear the echo distinctly, will the distance from the source of sound to the reflecting surface be same at all temperatures? Explain your answer.

Answer 1

• No, the distance from the source of sound to the reflecting surface will not be the same at all temperatures. 
• Velocity of sound is directly proportional to the square root of temperature. 
• One of the conditions of echo is that the time interval between the original and reflected sound should be more than 0.1 sec. 
• So if the temperature increases, the velocity of sound increases and the reflected sound reaches in less than 0.1 sec. 
• So for echo to be heard the distance between the observer and the reflecting surface has to increase.