Unit 3- Earth Geometry Flashcards
What is latitude vs longitude?
Latitude is a horizontal line (left to right)
Longitude is vertical (up and down)
How many minutes is 1 degree?
1 degree= 60 minutes
How do we use minutes?
Minutes is a fraction of a minute, therefore, we can use them to be more accurate. For example, 2degrees 3 minutes.
How many degrees is the equator?
The equator represents 0 degrees. This is the middle horizontal.
How do we measure lines of latitude?
The equator is 0 degrees. Therefore, each line of latitude is measured in degrees North or South from this equator.
How do we measure lines of longitude?
The prime meridian is 0 degrees. Therefore, each line of longitude is measured in degrees East or West from this equator.
What is a great circle vs a small circle?
Great circle= travelling up and down
Small circle= travelling left and right
For a great circle how many km is 1 degree on Earth?
For a great circle, 1 degree= 111.2km
For a small circle how do we go from degrees to km?
1 degree= 111.2 cos (theta)
(this answer makes the amount of km)
Therefore, we times this by the angular distance but the theta is the degrees of the horizontal line.
How do you find angular distance?
** if they are on the SAME side of the equator or meridian, MINUS the two angles.
** if they are on DIFFERENT sides of the equator or meridian, ADD the two angles.
Great circle: use the N/S angles
Small circle: use the E/W angles
What is the rule for speed, time, and distance.
Imagine a triangle.
D on top
S and T on the bottom
middle line is multiply
two top lines is divide
What are the translations between time and degrees.
When the earth rotates 360 degrees (full rotation), 24 hours passes.
1degree= 4 minutes
15degree= 1 hour
What is GMT?
Greenwich mean time is the universal time term, which is 0. Every time zone is GMT + or - an amount from it
