Pg.461-number+20


 * Pg.461 #20 **
 * a) ** The surfaces that are found in a city are mainly conductors that absorb solar radiation and emit infrared radiation therefore, being high-in-albedo. Although, the surfaces found in a forested area are mainly insulators or poor conductors of heat. For example, wood is a poor conductor of heat.
 * b) ** White rock
 * c) ** White rock is evidently a white surface that does not absorb heat; therefore, it cannot give off heat when it comes to giving it off at night. White rock reflects the heat given off but asphalt and concrete absorb heat.
 * d) ** Tar
 * e) ** Tar is dark whereas in pale colored shingles are light so, since we know that darker coloured objects absorb heat easily and make releasing it difficult, we know that tar would take the longest to cool. Also, Tar is made up of oil products, making it a great conductor.
 * f) ** An urban heat island consists of materials with great conduction. Conduction is the transfer of thermal energy from one substance to another. The materials used to form the city have great conduction; therefore they are great conductors. Materials like concrete and asphalt are great conductors. Also, urban areas consist of tall buildings mainly so, it’s very hard for heat to escape. Motor vehicles are also great up the environment.
 * g) ** At night when infrared radiation is released, it slowly heats the atmosphere, causing the air temperature to rise. But, since air has a current, it shifts to other areas.

Sana ; Javaheri  <span style="font-family: 'Arial','sans-serif'; font-size: 72pt;">