- Sound travels in matter media (solid, liquid and gas) and it does not spread into space. Sounds too intense have implications for the hearing.
Concentration of energy with the thin lens convergent. Safety: danger of direct observation of the sun through a converging lens. Vision results from the formation of an image on the retina.
Difficulty making transitions (from activity to activity or class to class); takes an excessive amount of time to find pencil, gives up, refuses to leave previous task; appears agitated during change.
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Monochromatic light, polychromatic light, frequency and color.
Propagation of light in transparent media, index of the medium.
Speed of light in vacuum (3x108 m / s or 300,000 km / s).