On a winter morning the speed of sound in air is 320m/s. A boy whistles facing a cliff that is 200m away.
(i) Calculate the time after which he hears the echo.
(ii) Later in the day the air temperature rises so that the speed of sound becomes 340m/s. By how much does the echo time change compared to part (i)?
a. (i) Time after which the echo is heard
b. (ii) Change in echo time when speed becomes 340m/s