Theory question 203
Latitude, Longitude and Time(a) What are the similarities and differences between the lines of latitude and longitude?
(b) An international cricket match between The Gambia and India is scheduled to start in Banjul (longitude 16°W) at 9.00a.m local time on 26th June. Calculate the time and day that listeners will have to tune to their radios for the start of the commentary at (i) Bombay (74°E) (ii) Pitsburg (89°W).
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(a) Similarities: both imaginary lines; both measured in degrees; together they locate places (grid)
Differences: latitude – parallels running east-west, 0-90° N/S, all parallel, lengths decrease towards the poles, used for distance/climate zones; longitude – meridians running north-south, 0-180° E/W, meet at the poles, all equal length, used for time
(b)(i) Bombay: 74 + 16 = 90°; 90 ÷ 15 = 6 h; east, so add: 9.00 a.m. + 6 h = 3.00 p.m., 26th June
(ii) Pitsburg: 89 − 16 = 73°; 73 × 4 min = 292 min = 4 h 52 min; west, so subtract: 9.00 a.m. − 4 h 52 min = 4.08 a.m., 26th June
Add time going east, subtract going west; 1° = 4 minutes.