In other words, the distance traveled by the sound wave in 1 second is equivalent to the 170 meters down to the canyon wall plus the 170 meters back from the canyon wall. Remember, when there is a reflection, the wave doubles its distance. In this instance, the sound wave travels 340 meters in 1 second, so the speed of the wave is 340 m/s. He shouts and hears the echo of his voice one second later. A classic physics problem goes like this: Noah stands 170 meters away from a steep canyon wall. The result is that you hear the echo (the reflected sound wave) of your holler. The sound wave travels through the medium (air in this case), reflects off the canyon wall and returns to its origin (you). When you let out a holler within a canyon, you often hear the echo of the holler. Reflection phenomena are commonly observed with sound waves. That is, by reflecting back to the original location, the wave has traveled a distance that is equal to twice the length of the slinky. A slinky wave that travels to the end of a slinky and back has doubled its distance. In the case of a slinky wave, the disturbance can be seen traveling back to the original end.
When a wave undergoes reflection, it remains within the medium and merely reverses its direction of travel. The wave will reflect or bounce off the person's hand. One behavior that waves undergo at the end of a medium is reflection. For example, a wave introduced by a person into one end of a slinky will travel through the slinky and eventually reach the end of the slinky and the presence of the hand of a second person.
Sometimes a wave encounters the end of a medium and the presence of a different medium. The faster wave travels a greater distance in the same amount of time. On the other hand, if the crest of an ocean wave moves a distance of 25 meters in 10 seconds (the same amount of time), then the speed of this ocean wave is 2.5 m/s. If the crest of an ocean wave moves a distance of 20 meters in 10 seconds, then the speed of the ocean wave is 2.0 m/s. In the case of a wave, the speed is the distance traveled by a given point on the wave (such as a crest) in a given interval of time. The speed of an object refers to how fast an object is moving and is usually expressed as the distance traveled per time of travel. If one watches an ocean wave moving along the medium (the ocean water), one can observe that the crest of the wave is moving from one location to another over a given interval of time. A wave is a disturbance that moves along a medium from one end to the other.