A boy standing in front of a high cliff claps his hands and hears the echo of the clap after 2.4s. The speed of sound in the air at that time is 330m/s.
(i) Calculate the distance of the boy from the cliff.
(ii) The boy then walks 30m closer to the cliff and claps again. Keeping the speed of sound the same, determine the new time interval between the clap and the echo.