(a) (i) With the aid of a diagram, identify the main lines of latitude.
(ii) Calculate the distance between Addis Ababa in Ethiopia (latitude 10°N) and Maseru in Lesotho (latitude 30°S).
(b) (i) Define the revolution of the earth.
(ii) Describe how the revolution of the earth affects the length of day and night in the Northern Hemisphere.
Explanation
(a) Main lines of latitudes an Arctic circle (66’/,°N)
(b) Tropic of cancer PT/2°N)
(c) Equator (0°)
(d) Tropic of capricorn (23’12°S)
(e) Antarctic circle (66’/,’S)
(a) Latitude of Addis Ababa = 10°N
(b) Latitude of Maseru = 30°S
(c) Latitudinal difference = 10° + 30° = 40°
(d) Since 1° = 111km or 111.1km
(e) 40° = 4440km or 4444km
(b) Solution
i. Revolution of the earth is the movement of the earth around the sun in its orbit
ii. Effects of revolution on the lengths of day and night in the Northern Hemisphere
(a) The length of day and night varies depending on the position of the earth in relation to the sun.
(b) The periods of daylight increase during summer as we move towards the north pole.
(c) At the Arctic Circle (66’/2°N), there is a complete 24-hour period of continuous daylight on June 21.
(d) The region from the Arctic Circle to the north pole at this time is called ‘the land of the midnight sun.”
(e) This period is when the sun is overhead at the Tropic of Cancer,
(f) In the winter period, around December 22, the hours of darkness increase towards the North Pole.
(g) The sun never rises at the Arctic circle
(h) There is complete darkness for the whole day on December 22
(I) The sun is directly overhead at the Tropic of Capricorn during this period.
(j) There is equal day and night during the equinox
(k) The sun is directly overhead at the equator on March 21 and September 23