Answer: 84.63 m
Explanation:
The speed of sound in the air, at [tex]0 \°C[/tex] is [tex]331.5 m/s[/tex], and for each degree Celsius the temperature rises, the speed of the sound increases by [tex]0.6 m/s[/tex]. So, if we estimate the speed of sound at [tex]30 \°C[/tex] it will be [tex]349 m/s[/tex].
On the other hand, the speed of sound [tex]V[/tex] is defined as the distance traveled [tex]d[/tex] in a especific time [tex]t[/tex]:
[tex]V=\frac{d}{t}[/tex]
Where:
[tex]V=349 m/s[/tex] is the speed of sound
[tex]t=\frac{0.485 s}{2}=0.2425 s[/tex] is half the time the sound wave travels since you say "hello", the sound wave hits the building and then returns to you
[tex]d[/tex] is the distance between you and the building
[tex]349 m/s=\frac{d}{0.2425 s}[/tex]
Finding [tex]d[/tex]:
[tex]d=(349 m/s)(0.2425 s)[/tex]
Finally:
[tex]d=84.63 m[/tex]
