Geography Questions: Figuring Out Degrees?

Question

Please show details and explain as thoroughly as possible. It's hard for me to understand, especially finding longitude:

1. How many degrees of latitude lie between 17 North and 32 South?

2. How many degrees of longitude lie between 168 East and 32 South.

Thanks for any help!

Answer 1

1. 17 N & 32 S are on either side of equator. So add them. Result is 49 degrees difference.

2. 168 E & 177 W are again not on the same side but both end up at 180 which is both E & W. 168 E is 12 (=180-168) before 180. 177 W from the other side of 180 is 3 (=180-177)from it. So you need to add them. Result is 12+3=15, that is the difference between them.

Answer 2

1. 5445 km

2. 1667 km

With reference to the above answer: you have to do the conversion from degrees, minutes and seconds to derive your answers.

Answer 3

Latitude is measured from 0 degrees at the equator. To find the difference in degrees between two latitudes on the same hemisphere, you have to substract them. To find the difference between two latitudes on different hemisphere, you have to add them. So between 17 N and 32 S, there is 49 degrees. One degree of latitude is 60 minutes of a degree and also what is called a Nautical Mile, which is 1,852 meters.

Longitudes are measured from an arbitrary line that is the Greenwich prime meridian. You did a typo writing 'longitude 32 south' because longitudes are east or west. Assuming that it is then 32 west, the difference between 168 E and 32 W is 200 degrees.

Because longitudes are narrowing near the poles, one degree of longitude is one degree of latitude multiplied by the cosine of that latitude. For example, I live near Oslo, Norway, that is at latitude 60N. Cosine 60 is 0.5 and one degree of longitude here is half one degree of latitude.

Latitudes are measured that way because in the old days, the only way to find a position was to measure the elevation of the North Star over the horizon. But to find a longitude one needs to find the angular distance with a reference point and that needs to know exactly the time. It was not before the late 18th century that John Harrison made the first reliable maritime chronometer and gave seafarers a chance to know their longitude.

That little knowledge of the longitude is the reason Christopher Columbus thought that the route from Spain to India was shortest westward, which it is not.