Answer:
[tex]x = 445.9\,m[/tex]
Explanation:
The velocity of sound in air at 20 °C is 343 meters per second. The distance of mountain can be derived by the following expression:
[tex]2\cdot x = v_{air}\cdot \Delta t[/tex]
[tex]x = \frac{v_{air}\cdot \Delta t}{2}[/tex]
[tex]x = \frac{(343\,\frac{m}{s} )\cdot (2.6\,s)}{2}[/tex]
[tex]x = 445.9\,m[/tex]