Originally Posted by captaa
Q4
The total length of the 53°N parallel of latitude on a direct Mercator chart is 133 cm. What is the approximate scale of the chart at latitude 30°S?
A)1 : 30 000 000 B)1 : 18 000 000 C)1 : 21 000 000 D)1 : 25 000 000
Originally Posted by captaa
how is dep at 53N is 12999?
Since, a standard mercator of whole earth will show all meridians, you can take dLong as 360 deg.:
Departure
=dLong(in mins) x cos Lat
=360 x 60 x cos53
=12,999nm