Answer the following questions briefly,
(a) What is the angle of inclination of the earth's axis with its orbital plane?
(b) Define rotation and revolution.
(c) What is a leap year?
(d) Differentiate between the Summer and Winter Solstice.
e) What is an equinox?
f) Why does the Southern Hemisphere experience Winter and Summer Solstice
in different times than that of the Northern Hemisphere?
g) Why do the poles experience about six months day and six months night?
Answers
(a) The angle of inclination of the earth is 23.5 degrees.
(b) Rotation can be defined as the continuous motion of spinning around its axis. Revolution is the the circular motion of the earth on its orbital plane around the sun.
(c) The earth takes approximately 365 days and 6 hours to complete one revolution around the sun. After 4 years, these 6 hours add up to form a 24 hours day, which add to that year. This year is known as a leap year, having 366 days.
(d) Summer solistice is the phenomenon when the sun is directly over the tropic of cancer or capricorn, for which the respective hemisphere has to experience a longer day. Winter solistice is the vice versa of the former, where when one hemisphere is experiencing summer solistice, the other experiences winter.
(e) Equinox is a phenomenon when the sunlight falls directly over the equator. On the day of occurence of this phenomenon, the earth experiences equal days and nights.
(f) This is so because of the tilt of the earth, which causes different seasons at the same time in the two hemispheres, thus causing different solistices at the same time too.
(g)During the time of summers in northern hemisphere, the sunlight falls more readily on it than in winters. So in the north pole, because of smaller diameter of arctic circle, the sunlight covers the whole of the area. Same is the case with the south pole when the southern hemisphere experiences summers.