(4) The Angle of the Sun's Rays
causes greater heating of the ground.
Part of a high school course on astronomy, Newtonian mechanics and spaceflight
by David P. Stern
This lesson plan supplements:|
#4 "Angle of the Sun's Rays" at Sunangle.htm,
on the web http://www.phy6.org/stargaze/Sunangle.htm
Goals: The student will learn|
Terms: Elevation (or height) of the Sun above the horizon.
Stories and extras: The reason why lichens in a forest grow on the north side of tree trunks, why solar collectors face south and are inclined, and why French wine grape growers treasure vineyards on slopes facing south.
The placement of windows--facing south in cold climates, facing north in hot climates, and the use of overhangs.
Guiding questions and additional tidbits
The questions below may be used in the presentation, the review afterwards or both, and suggested answers are provided. Brackets [ ] enclose comments by the teacher or optional material.
-- At any given place, at what time of the day do the Sun's rays fall most steeply (towards the perpendicular) onto the ground? At what time of the day do they fall least steeply?
-- Does the Sun heat the ground more when its rays fall more steeply? Why?
-- In the summertime in northern Alaska, the Sun never sets. Still, it does not get very hot there. Why?
-- In the US, how would you orient a solar collector (for heating water or generating electricity) to collect sunlight most efficiently? And in Argentina?
-- In the hot climate of Texas or New Mexico, Where should the main windows of the house face?
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Author and Curator: Dr. David P. Stern
Mail to Dr.Stern: audavstern("at" symbol)erols.com .
Last updated: 12.17.2001