Echoes work through the reflection of sound waves. When a person shouts into a well or canyon, and they hear an echo, it is because the sound waves reflect from the canyon wall or the bottom of the well and travel back to the person's ears.Know More
An echo works by initially producing sound, which is done by rushing air from the lungs past the vibrating vocal chords. The vibrations of the vocal chords cause the rushing air to fluctuate, which creates a sound wave. Essentially, a sound wave is just one particular moving pattern of fluctuations in air pressure.
The changing air pressure of the sound wave pushes out surrounding air particles and then pulls them in. These particles then push and pull the particles next to them, causing the sound wave to travel. When a person shouts, the sound wave produced travels across an area. The moment that the sound wave meets a solid, such as a rock face in a canyon, changing air pressure is reflected back, and the sound wave moves in the opposite direction towards the person who initially made the sound.
In certain areas, where air pressure and air composition are constant, it's possible to determine distance, such as the width of a canyon or the depth of a well.Learn More
Spherical aberration in mirrors is usually corrected by using a mirror which is not a sphere. A parabolic mirror is often used instead of a spherical mirror. In lenses, the simplest method for minimizing spherical aberration is to use an aperture in front of the lens. Symmetric doublets, such as the orthoscopic doublet, are also efficient in greatly reducing the spherical aberration in lenses.Full Answer >
An echo can be heard in a cave when a sound reflects off surrounding walls and then is heard again. It is also possible to hear an echo in an empty room, in a mountain valley, under a bridge or by calling down into a well.Full Answer >
Rainbows appear curved because sunlight shines into raindrops. The sunlight then leaves the raindrop at a different angle than when it first entered, resulting in a curved shape.Full Answer >
In addition to the role it plays in driving the water cycle and affecting climate and weather, the energy received from the sun also makes possible the process of photosynthesis, which maintains the atmospheric levels of oxygen required for aerobic organisms to exist on Earth. The light energy captured by plants through photosynthesis is also the source of the energy stored in the organic compounds that provide the greater portion of the energy required for multicellular life to continue. The solar energy stored in fossil fuels and released through burning for human use represents another important role played by sunlight.Full Answer >