6. = The distance to an object can be calculated by using the time it takes for an echo to be heard: Distance = speed of sound x 1/2 time for echo to return A person is standing at an unknown distance from a wall. We want to know how far away the wall is from the person. The speed of sound is 344 meters per second. The person yells, and the echo takes 1.4 seconds to return. How far away is the wall in meters? Show calculations below.