Globe: Latitudes and Longitudes

A globe is a true model of the Earth, tilted on its axis at 66.5 degrees to the plane of its orbit. The imaginary line round the middle of the globe, dividing it into the Northern and Southern Hemispheres, is the Equator. Lines drawn parallel to it are parallels of latitude, measured from 0 degrees at the Equator to 90 degrees at the poles. In this chapter you will study the Tropic of Cancer (23.5 degrees N), the Tropic of Capricorn (23.5 degrees S), the Arctic Circle (66.5 degrees N) and the Antarctic Circle (66.5 degrees S), and the Torrid, Temperate and Frigid heat zones they mark. You will then learn about meridians of longitude, which run from pole to pole. The Prime Meridian (0 degrees) passes through Greenwich near London. As the Earth rotates 360 degrees in 24 hours, local time changes by one hour for every 15 degrees, or 4 minutes per degree. Indian Standard Time, based on 82.5 degrees E, is 5 hours 30 minutes ahead of Greenwich Mean Time.

Detailed Worksheet: Globe: Latitudes and Longitudes Section A - Definitions (10 marks) 1. What is a globe? Why is it called a true model of the Earth? (2 marks) 2. What is the Equator? Why is it an important line of reference? (2 marks) 3. Define parallels of latitude and meridians of longitude. (2 marks) 4. What is the Prime Meridian? Through which place does it pass? (2 marks) 5. What is standard time? Why does a country need a standard time? (2 marks) Section B - Calculations and Applications (15 marks) 6. The Earth rotates through 360 degrees in 24 hours. (i) How many degrees does it rotate in one hour? (ii) How many minutes does it take to rotate through 1 degree? (iii) How long does it take to rotate through 45 degrees? (3 marks) 7. When it is 12 noon at Greenwich (0 degrees), find the local time at (i) 30 degrees E (ii) 45 degrees W (iii) 90 degrees E. (3 marks) 8. Indian Standard Time is based on the standard meridian of 82.5 degrees E. (i) Calculate how far ahead of Greenwich Mean Time IST is. (ii) If it is 8 a.m. at Greenwich, what is the time in India? (iii) Through which town near Prayagraj does this meridian pass? (3 marks) 9. India extends from about 68 degrees E to 97 degrees E. (i) Find the difference in longitude. (ii) Find the difference in local time between the easternmost and westernmost points. (iii) Why does India have one standard time? (3 marks) 10. Name the heat zone in which each place lies and give the reason: (i) a place at 10 degrees N (ii) a place at 45 degrees S (iii) a place at 75 degrees N. (3 marks) Section C - Diagrams (10 marks) 11. Draw a diagram of the globe showing the Equator, the Tropic of Cancer, the Tropic of Capricorn, the Arctic Circle, the Antarctic Circle, the North Pole and the South Pole, with their latitudes. (4 marks) 12. Draw a diagram showing the heat zones of the Earth (Torrid, North and South Temperate, North and South Frigid) and the sun's rays falling on each. (3 marks) 13. Draw a diagram showing the Prime Meridian, the 180 degree meridian, and the Eastern and Western Hemispheres. (3 marks) Section D - Analysis and Higher-order Thinking (15 marks) 14. The Torrid Zone receives the maximum heat. (i) Explain why, in terms of the angle of the sun's rays. (ii) Why do the Frigid Zones remain very cold? (iii) Why do the Temperate Zones have moderate temperatures? (iv) In which zone does most of India lie? (5 marks) 15. A cricket match is being played in London starting at 10 a.m. local time (GMT). (i) What time will it start in India? (ii) If the match lasts 8 hours, at what time will it end in India? (iii) Why do Indian viewers watch some matches late at night when they are played in places west of London? (iv) Why do countries such as Russia have several time zones? (5 marks) 16. Latitude and longitude together help locate any place. (i) What is a grid? (ii) Explain how you would locate a place at 20 degrees N and 80 degrees E on a globe. (iii) Why are both latitude and longitude needed? (iv) Give one practical use of this system. (5 marks) Instructions: Time allowed 2 hours. Attempt all sections. Show all steps in time calculations, and use N, S, E and W with every latitude and longitude.