Chapter 17 Longitudes Latitudes 1252022 FYHSKulai Chtan 1

Chapter 17 Longitudes & Latitudes 1/25/2022 FYHS-Kulai, Chtan 1

longitudes N latitude S 1/25/2022 FYHS-Kulai, Chtan 2

1/25/2022 FYHS-Kulai, Chtan 3

子午线 The prime Meridian N West Equator 赤道 S 1/25/2022 East North FYHS-Kulai, Chtan South 4

latitudes 纬线 1/25/2022 FYHS-Kulai, Chtan 5

N (0 degree Equator) Center of the circle 1/25/2022 S FYHS-Kulai, Chtan 6

N P Q O S 1/25/2022 If , we said that the position of P is. FYHS-Kulai, Chtan The side view is shown on next slide 7

N 北纬 P Q O Equator S 1/25/2022 FYHS-Kulai, Chtan 8

The side view of the earth : N R: radius of the earth=6370 km O r 1 r 2 r 3 S 1/25/2022 FYHS-Kulai, Chtan E r 1, r 2, r 3 are radius of each small circle 9

R=6370 km R 1/25/2022 FYHS-Kulai, Chtan 10

How to calculate the radius of small circles? N P Q r O S 1/25/2022 FYHS-Kulai, Chtan 11

e. g. 1 Find the difference between the latitudes: (a) (b) 1/25/2022 FYHS-Kulai, Chtan 12

Soln : (a) Difference between latitudes (b) Difference between latitudes 1/25/2022 FYHS-Kulai, Chtan 13

e. g. 2 Find the difference between the latitudes: (a) (b) 1/25/2022 FYHS-Kulai, Chtan 14

Soln : (a) Difference between latitudes (b) Difference between latitudes 1/25/2022 FYHS-Kulai, Chtan 15

longitudes 经线 1/25/2022 FYHS-Kulai, Chtan 16

N B C A O D Greenwich Meridian S 1/25/2022 FYHS-Kulai, Chtan 17

Longitude of A and B are Longitude of C and D are 1/25/2022 FYHS-Kulai, Chtan 18

N What is the position of R? O P Q R Greenwich Meridian S 1/25/2022 FYHS-Kulai, Chtan 19

Viewing from the top of N So, R is O P R Greenwich Meridian 1/25/2022 Q FYHS-Kulai, Chtan 20

e. g. 2 Given that and , find the difference between P and Q. 1/25/2022 FYHS-Kulai, Chtan 21

Soln : Latitude O P Q G 1/25/2022 E So, angle POQ is FYHS-Kulai, Chtan 22

Some important facts : 1. Radius of the Earth = 6370 km 2. 1 nautical mile = 1. 853 km 3. Arc length of a circle = , where is in radians 4. Radius of small circle , 1/25/2022 FYHS-Kulai, Chtan 23

5. 6. 1’ = 1 nautical mile 海里 7. 1 hour = 1/25/2022 FYHS-Kulai, Chtan 24

e. g. 3 Find the distance between P and Q in (a) nautical miles , (b) in km of e. g. 2 1/25/2022 FYHS-Kulai, Chtan 25

Soln : Latitude PO=r O P Q G 1/25/2022 FYHS-Kulai, Chtan 26

1/25/2022 FYHS-Kulai, Chtan 27

e. g. 4 1/25/2022 FYHS-Kulai, Chtan 28

Soln : N O P Distance E between PQ =105 x 60’ Q =6300 n. m. S Distance between PQ=6300 x 1. 853 km =11, 673. 9 km 1/25/2022 FYHS-Kulai, Chtan 29

e. g. 5 If the standard time (标准时) of London is 9 am (0900), find the local time of Tokyo. 1/25/2022 FYHS-Kulai, Chtan 30

Soln : L has the same logitude as Greenwich i. e. zero degree. O L T 1/25/2022 The time difference between L and T : FYHS-Kulai, Chtan 31

Tokyo is on the East side of London. i. e. It is 06: 20 pm 1/25/2022 FYHS-Kulai, Chtan 32

e. g. 6 1/25/2022 FYHS-Kulai, Chtan 33

Soln : Sydne Longitude difference between 2 cities : NY G Time difference Local time of Sydne is i. e. afternoon 4 o’clock. 1/25/2022 FYHS-Kulai, Chtan 34

e. g. 7 1/25/2022 FYHS-Kulai, Chtan 35

Soln : A and B are both on the same longitude : 110 degree East A O 1/25/2022 B Distance between A and B = 2000 km E FYHS-Kulai, Chtan 36

A O B E So, the latitude of A is : Hence, the location of A is 1/25/2022 FYHS-Kulai, Chtan 37

e. g. 8 1/25/2022 FYHS-Kulai, Chtan 38

Soln : N r O Q 1/25/2022 O P P/Q E S FYHS-Kulai, Chtan 39

= 6065. 98 km = 6065. 98 / 1. 853 n. m. = 3273. 60 n. m. 1/25/2022 FYHS-Kulai, Chtan 40