During a physics project, students measure the distance to a tall building across a lake using echoes. They stand at the water's edge when the air temperature is 15∘C, for which the speed of sound is 340m s−1. They clap and record the time interval of 3.40s between the sound and its echo. The next morning the temperature drops to 5∘C. The speed of sound decreases by 0.6m s−1 for every 1∘C fall in temperature. Answer the following.
(a) Calculate the distance to the building from the students' position using the first observation.
(b) Determine the speed of sound in air at 5∘C.
(c) If the students repeat the clap at 5∘C without changing their position, find the new time interval between the clap and its echo.