A person yells across a canyon and hears an echo 2.5 seconds later. The air temperature is 21°C. How far away is the canyon wall?

The canyon wall is 850 m away from the person

Explanation:

Well, the speed of sound in air at is defined as , this can be calculated by the following equation:

(1)

Where:

is the Heat capacity ratio for air

is the Universal Gas constant

is the temperature in Kelvin

is the air molar mass

(2)

Now that we know the speed of sound, we can use the following equation to find the distance between the person and the canyon wall:

(3)

Where:

is the distance between the person and the canyon wall

is the time it takes to the sound wave to travel from the person and then go back

Isolating :

(4)

(5)

Finally:

come closer and become far apart and become steam/gas

their crystal patterns have been disrupted by stress