The following 3 positions are given:
A) 0238N 17832E
B) 0317N 17615W
C) 0249S 17905W
Q1 - What is ch lat B - C?
What is the formula for finding change of latitude (Q1)
Change of latitude is simply the difference between the initial latitude and the final latitude. If both latitudes had be North or if both had been south we would simply subtract the initial latitude from the final latitude. But in this case one is north of the Equator and the other is south of the equator. So the change in latitude is the sum of the two (0317 + 0249) = 0606. C is south of B so the change in longitude is 6 degrees 6 minutes to the South. Ch long is usually expressed in minutes because the ground distance (or departure) between any two points of longitude at the same latitude = Ch Long (in minutes) x Cos latitude.
Q2 - What is d long A - B?
what are they looking for in Q2? Answers should be given in degrees and minutes.
Dlong is the difference between the final longitude and the initial longitude. As with change in latitude, if they were both at the same side of the reference point (in this case 180EW) we would subtract the initial from the final. In this case they are at opposite sides of the reference 180EW so we normally add them together. But in this case the shortest route is going East from 17832E past the 180EW to 17615W. From 17832E to 180EW is a change of 1 degree 28 minutes to the East. And from 180EW to 17615W the change is 3 degrees 45 minutes to the East. Adding the two together gives a total change of 5 degree 13 minutes to the East.
Q3 - . A, B and C represent islands forming the HARRY ISLANDS.
A group of tourists is chartering a plane to take them to THE WESTERN HARRY ISLAND. To which of the islands would you take them?
To go from A to C we must go from 17832E past 180EW to 17905W. This is a change of 2 degrees 23 minutes to the East. So to go from C to A we must go 2 degrees 23 minutes to the West. So the most westerly of the three points is island A.