Optics & Waves

A:

An echo occurs when a sound wave reflects back towards its source after hitting a hard surface. Although the surface may absorb some of the sound, the remaining sound that is not absorbed continues moving, creating additional echoes by bouncing off surrounding objects until the sound is completely absorbed or dissipates.

See Full Answer
Filed Under:
  • How Do Magnifying Glasses Make Things Look Bigger?

    Q: How Do Magnifying Glasses Make Things Look Bigger?

    A: An observer's perception of an object being examined changes with a magnifying lens because the lens bends the light rays from the object, thus distorting the size of the image formed, making it appear bigger. Light rays bend due to a change in density as they move from air to the glass that forms the lens. If light rays did not bend, no magnification would occur.
    See Full Answer
    Filed Under:
  • What Is the Speed of Light in Water?

    Q: What Is the Speed of Light in Water?

    A: The speed of light in water is approximately 225,000 km per second. While enormously fast, this is notably slower than the speed of light in a vacuum, which is 300,000 km per second.
    See Full Answer
    Filed Under:
  • What Are Optical Fibers Made From?

    Q: What Are Optical Fibers Made From?

    A: Commercial optical fiber cables use highly purified glass for their cores, glass or polymers for their cladding, and polyurethane for their jackets. Some optical fiber cables use plastic cores, which are cheaper; however, this type of cable has a higher signal loss and works at shorter ranges than glass. Both types transmit light signals using reflection along the axis of the core.
    See Full Answer
    Filed Under:
  • How Do Waves Carry Energy From One Place to Another?

    Q: How Do Waves Carry Energy From One Place to Another?

    A: Energy is transferred in electromagnetic waves by vibrations in electric and magnetic fields. The vibration of air particles is energy transfer in sound waves, while the transfer of energy in water waves is the oscillation of water particles.
    See Full Answer
    Filed Under:
  • What Is a Spectrograph?

    Q: What Is a Spectrograph?

    A: A spectrograph splits or disperses light into its spectrum so it can be recorded and analysed. This can be done by using a prism or a diffraction grating.
    See Full Answer
    Filed Under:
  • What Causes a Mirage?

    Q: What Causes a Mirage?

    A: A mirage occurs when the air density difference caused by extremely hot temperatures causes photons to travel in a path other than a straight line. Hot air is less dense than cold air, so if there is a significant temperature gradient, the light reflected from an object may be refracted. This can distort the image.
    See Full Answer
    Filed Under:
  • What Is the Frequency Range of Radio Waves?

    Q: What Is the Frequency Range of Radio Waves?

    A: Radio waves range from 300 gigahertz (GHz), or a wavelength of 1 millimeter, to 3 kilohertz (kHz), which corresponds to a wavelength of 100 kilometers. Radio waves are the lowest frequency within the electromagnetic spectrum. The wavelength is the distance from the peak of one wave to the next.
    See Full Answer
    Filed Under:
  • What Causes Light Refraction?

    Q: What Causes Light Refraction?

    A: Refraction is caused by light passing from one medium to another (from air to water, for example) and experiencing a change in speed. A fisherman looking into water to spear a fish will have to remember that refraction will distort the image he sees under the water's surface.
    See Full Answer
    Filed Under:
  • What Are the Physics of a Megaphone?

    Q: What Are the Physics of a Megaphone?

    A: A megaphone directs or funnels the voice to a specific direction, and it also regulates the distribution of sound waves from the mouth to the open medium. The secret behind the workings of a megaphone is in its shape.
    See Full Answer
    Filed Under:
  • What Is the Relationship Between Vibration and Sound?

    Q: What Is the Relationship Between Vibration and Sound?

    A: Sound is created through the vibration of air. When something produces vibrations, it creates sound waves. The movement of the vibration through the air is what people hear when they hear sound.
    See Full Answer
    Filed Under:
  • How Do We See Light?

    Q: How Do We See Light?

    A: The human eye sees light with the pupil and the retina. Located inside the retina are two types of special cells called photoreceptor cells. There are two varieties of photoreceptor cells known as cones and rods.
    See Full Answer
    Filed Under:
  • Does Sound Travel Faster Than Light?

    Q: Does Sound Travel Faster Than Light?

    A: Sound travels much more slowly than light. The speed of light is colloquially known as the cosmic speed limit as physical constraints prevent objects of macroscopic scale from traveling faster than light.
    See Full Answer
    Filed Under:
  • What Does the Loudness of a Sound Depend On?

    Q: What Does the Loudness of a Sound Depend On?

    A: Loudness is a subjective measure of sound because it is dependent upon the qualities of the sound receptor. Although loudness is related to decibel levels, sound pressure, frequency, bandwidth and duration, the actual perception of the sound is the proper variable for determining loudness.
    See Full Answer
    Filed Under:
  • How Did Sir Isaac Newton Discover Optics?

    Q: How Did Sir Isaac Newton Discover Optics?

    A: In 1666, Sir Isaac Newton discovered optics while examining a lighted refracted from a crystal prism and observing that light consisted of a full spectrum of color. In 1704, he published a book detailing his findings titled "Opticks."
    See Full Answer
    Filed Under:
  • What Happens to Wavelength As Frequency Increases?

    Q: What Happens to Wavelength As Frequency Increases?

    A: As frequency increases, wavelength decreases. Frequency and wavelength are inversely proportional. This basically means that when the wavelength is increased, the frequency decreases and vice versa.
    See Full Answer
    Filed Under:
  • Why Doesn't Sound Travel Through a Vacuum?

    Q: Why Doesn't Sound Travel Through a Vacuum?

    A: Sound does not travel through a vacuum because molecules of matter are required for sound to exist, and vacuums do not have any matter. The vibrations and movements of small particles of matter are what create sound and allow it to be heard. In a vacuum without any matter, such as space, it is impossible for sound to travel.
    See Full Answer
    Filed Under:
  • Why Are Lasers Red?

    Q: Why Are Lasers Red?

    A: Lasers are mostly red in color because red has the longest wavelength, approximately 650 nanometers. Because of this, red does not scatter easily and can be viewed from a long distance.
    See Full Answer
    Filed Under:
  • Where Do Ultraviolet Rays Come From?

    Q: Where Do Ultraviolet Rays Come From?

    A: Most of the ultraviolet rays that hit the Earth come from the sun. However, there are man-made items that give off ultraviolet rays, such as tanning beds, mercury vapor lamps and black lights.
    See Full Answer
    Filed Under:
  • How Does a Kaleidoscope Work?

    Q: How Does a Kaleidoscope Work?

    A: A kaleidoscope works by reflecting light that bumps into a reflective surface such as a mirror. It has two or more mirrors placed at an angle to each other. The mirror assembly is surrounded by a case, with an eyehole at one end of the mirrors and a collection of objects at the other end.
    See Full Answer
    Filed Under:
  • What Is Pitch in Physics?

    Q: What Is Pitch in Physics?

    A: Pitch, in physics, is equivalent to the frequency of sound waves, which are any compression waves in a medium. The word "pitch" is used specifically in situations where humans are perceiving the frequency of sound and changes in that frequency. Differences and changes in perceived pitch aren't always the same as the actual differences and changes in the frequencies of the sounds perceived.
    See Full Answer
    Filed Under:
  • What Is a Sonic Boom?

    Q: What Is a Sonic Boom?

    A: A sonic boom as an impulsive wave similar to thunder caused by an object exceeding the speed of sound, according to Sky-flash.com. The speed of sound is approximately 750 mph at sea level.
    See Full Answer
    Filed Under: