Answer:
494.45 m.
Explanation:
Echo: This is the sound heard after the reflection of sound wave in a plain surface.
v = 2x/t................................ Equation 1
Where v = velocity of sound in air, x = distance between the mountain and the hikers, t = time to hear the echo.
making x the subject of the equation,
x = vt/2........................... Equation 2
Given: v = 341 m/s, t = 2.9 s.
Substitute into equation 2
x = 341(2.9)/2
x = 494.45 m.
Hence the mountain is 494.45 m far away
