The time it takes to hear an echo can be gotten from the equation;
Where D is the distance to the wall, v is the speed of sound which is 750 miles per hour.
If it takes 3 seconds to hear an echo, the distance can be gotten by rewriting the equation as;
Therefore, we find out that;
Therefore, the wall is 1125 miles away.
b. To generalize the result;
If it takes n seconds to hear an echo, the distance to the canyon wall is;
Therefore, D = 375n