You are hiking along a trail in a wide, dry canyon where the outdoor temperature is t = 29.5° c. to determine how far you are away from the canyon wall you yell "hello" and hear the echo t = 1.8 s later.

The canyon is approximately 314 meters away

Explanation:

Speed of Sound

If we emit sounds in an open space where a large obstacle (like a mountain) is expected to return the sounds, then it will travel forth and back at a given speed for a certain time. We can assume the speed of sound is constant, so we could know the approximate distance of the mountain (or canyon in our case) by the known formula.

Where is the speed of sound and t is half the time we hear our echo.

The speed of sound in m/s can be calculated from the approximate formula in terms of the temperature T in degrees Celsius

We have , so

Let's compute x, for t=1.8/2=0.9 seconds

The canyon is approximately 314 meters away

the answer should be in the picture.