Sound and Light Review

1) In what units do we measure the loudness or intensity of sound? This is a logarithmic scale, why is this type of scale used?

2) What are several common uses for microwaves?

3) Explain why smooth surfaces make clear images and rough surfaces do not.

here is the material to find the answers.Refraction of Light Refraction is the bending of waves as they pass from one medium to another due to a change in the speed of the wave. This can cause images to appear to be in different locations. Waves can also change speed and bend when they pass through areas of different temperatures, causing a mirage.          The refraction of light bouncing off of the stick as the rays move from the water to the air causes the stick to appear to be broken.                   Dispersion Because different colors of light have different wavelength, they are refracted different amounts. This causes dispersion when multi-colored light changes mediums, breaking the light into its component colors. This is how rainbows are formed. As light passes through water in the air, the light rays are dispersed into all of the visible colors.  This rainbow is caused by the refraction and dispersion of white light into its 7 colors.    Lenses A lens is an object through which light rays pass. As they pass through the light rays bend due to refraction. There are two types of lenses: Converging or Convex Lens – In a lens like this the sides bend outwards. These cause the light rays to come together as they pass through the lens.  These are often used as magnifying glasses. Diverging or Concave Lens – These lenses have sides that bend inwards. These cause the light rays to diverge, or spread apart as they pass through the lens.  The two most common lenses are biconvex (equal curvature on both sides) and biconcave.  Both types of lenses can be used in camera lenses, telescopes, and to correct vision with glasses or contacts.    Click HERE to read about how the development of the telescope was dependent on mirrors and lenses.