The document provides steps for calculating time differences and longitude differences between two locations: 1) Find the longitude difference between the two places. 2) Convert the longitude difference to time using 1 hour = 15 degrees. 3) Adjust the calculated time based on whether the longitude is East or West - add time if East, subtract if West.

2. 𝒑𝒈 𝟕𝟖
Step 1: Find out the difference in
longitudes between two places given.
Step 2: Convert or change the difference in
longitude to time, 15° = 1 hour
Step 3: Adjust the time according to the
position of the longitude
if it is E, we add
if it is W, we subtract time.

3. 𝒑𝒈 𝟕𝟖 − 𝟕𝟗
Step 1: Find out the difference in
longitudes between two places given.
Step 2: Convert or change the difference in
longitude to time, 15° = 1 hour
Step 3: Adjust the time according to the
position of the longitude
if it is E, we add
if it is W, we subtract time.
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4. 𝒑𝒈 𝟕𝟗
Step 1: Find out the difference in
longitudes between two places given.
Step 2: Convert or change the difference in
longitude to time, 15° = 1 hour
Step 3: Adjust the time according to the
position of the longitude
if it is E, we add
if it is W, we subtract time.

5. 𝒑𝒈 𝟕𝟗

6. 𝒑𝒈 𝟕𝟗
𝑡𝑖𝑚𝑒 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 = 12.25 − 3.45 = 8.67 ℎ𝑟𝑠
𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑖𝑛 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒𝑠 = 8.67 ℎ𝑟𝑠 × 15 ° = 130 °
𝑃 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒 = 130 ° − 125 °
= 5 ° 𝐸
if local time of place x is ahead of the time at the given longitude, then the place is E of the given longitude
if local time of place x is behind of the time at the given longitude, then the place is W of the given
longitude
𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑖𝑛 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒𝑠 = 𝑃 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒 + 𝑄 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒
𝒔𝒊𝒏𝒄𝒆 𝑷 𝒊𝒔 𝑬, 𝑸 𝒊𝒔 𝑾, 𝒘𝒆 𝒂𝒅𝒅 𝒕𝒉𝒆 𝒅𝒊𝒇𝒇𝒆𝒓𝒆𝒏𝒄𝒆 𝒊𝒏 𝒍𝒐𝒏𝒈𝒊𝒕𝒖𝒅𝒆𝒔

7. 𝐴 (80 ° 𝑊) 8 𝑎𝑚
𝐵 (0 °) = 𝑔𝑟𝑒𝑒𝑛𝑤𝑖𝑐ℎ
𝐶
2000
60
° 𝐸 = 33.33 ° 𝐸
海里
𝑡𝑖𝑚𝑒 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 =
80
15
= 5 ℎ𝑟𝑠 20 𝑚𝑖𝑛
𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑖𝑛 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒𝑠 = 80 °
𝐵 𝑙𝑜𝑐𝑎𝑙 𝑡𝑖𝑚𝑒 = 8 ℎ𝑟𝑠 + 5 ℎ𝑟𝑠 20 𝑚𝑖𝑛
𝑩 𝒊𝒔 𝑬 𝒕𝒐 𝑨, 𝒘𝒆 𝒂𝒅𝒅 𝒕𝒊𝒎𝒆
= 13 ℎ𝑟𝑠 20 𝑚𝑖𝑛
𝐴 (80 ° 𝑊) 8 𝑎𝑚
𝑡𝑖𝑚𝑒 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 =
113.33
15
= 7 ℎ𝑟𝑠 33 𝑚𝑖𝑛
𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑖𝑛 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒𝑠
= 80 ° + 33.33 °
= 113.33 °
𝐵 𝑙𝑜𝑐𝑎𝑙 𝑡𝑖𝑚𝑒 = 8 ℎ𝑟𝑠 + 7 ℎ𝑟𝑠 33 𝑚𝑖𝑛
𝑪 𝒊𝒔 𝑬 𝒕𝒐 𝑨, 𝒘𝒆 𝒂𝒅𝒅 𝒕𝒊𝒎𝒆
= 15 ℎ𝑟𝑠 33 𝑚𝑖𝑛

8. 𝒑𝒈 𝟕𝟗

9. 𝐴 = 𝑊 𝑜𝑓 𝑆
𝑆 (104 ° 30’ 𝐸)
𝑡𝑖𝑚𝑒 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 = 3 ℎ𝑟𝑠
𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑖𝑛 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒𝑠 = 3 ℎ𝑟𝑠 × 15 ° = 45 °
𝒔𝒊𝒏𝒄𝒆 𝑨 𝒊𝒔 𝑾 𝒐𝒇 𝑺 (𝒃𝒖𝒕 𝒔𝒕𝒊𝒍𝒍 𝒔𝒂𝒎𝒆 𝒅𝒊𝒓𝒆𝒄𝒕𝒊𝒐𝒏 𝒇𝒓𝒐𝒎 𝒈𝒓𝒆𝒆𝒏𝒘𝒊𝒄𝒉),
𝒘𝒆 𝒔𝒖𝒃𝒕𝒓𝒂𝒄𝒕 𝒕𝒉𝒆 𝒅𝒊𝒇𝒇𝒆𝒓𝒆𝒏𝒄𝒆 𝒊𝒏 𝒍𝒐𝒏𝒈𝒊𝒕𝒖𝒅𝒆𝒔
𝐴 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒 = 104 ° 30’ − 45 °
= 59 ° 30’ 𝑬
𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑖𝑛 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒𝑠 = 𝑆 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒 − 𝐴 𝑙𝑜𝑛𝑔𝑖𝑡𝑢𝑑𝑒

10. 20° 𝑁
35° 𝑆

11. 海里

12. 𝒑𝒈 𝟖𝟎

15. 𝒑𝒈 𝟖𝟏
Town A is 2000 km N to Town B
A coodinate = ?

16. 𝒑𝒈 𝟖𝟏
(a) PQ = ?
(b) if speed = 1200 km/h, h = ?

17. 𝒑𝒈 𝟖𝟐
5° 24’
(31° 40’ 𝑁, 115 ° 10’ 𝐸)
(8 ° 30’ 𝑆, 100 ° 𝐸)
6° 40’
47° 10’ 𝑁

18. =
700
60
𝐶 (35 ° 10’ 𝑁)
𝐷
= 11 ° 40’
𝒑𝒈 𝟖𝟐
𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑖𝑛 𝑙𝑎𝑡𝑢𝑑𝑒𝑠 = 𝐷 𝑙𝑎𝑡𝑖𝑡𝑢𝑑𝑒 − 𝐶 𝑙𝑎𝑡𝑖𝑡𝑢𝑑𝑒
𝐷 𝑙𝑎𝑡𝑖𝑡𝑢𝑑𝑒 = 11 ° 40’ + 35 ° 30’
= 47 ° 10’ 𝑁

19. 𝒑𝒈 𝟖𝟐
33° 20’

20. 𝒑𝒈 𝟖𝟐
𝐵 (6 ° 4’ 𝑁)
𝐴 (2 ° 12’ 𝑁)
𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑖𝑛 𝑙𝑎𝑡𝑖𝑡𝑢𝑑𝑒𝑠 = 𝐵 𝑙𝑎𝑡𝑖𝑡𝑢𝑑𝑒 − 𝐴 𝑙𝑎𝑡𝑖𝑡𝑢𝑑𝑒
= 6 ° 4’ − 2 ° 12’
= 3 ° 52’
= 3.87 °
𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 =
3.87 °
360 °
× 2𝜋 × 6,370 𝑘𝑚
= 430 𝑘𝑚

21. 海里
=
2000
60
= 33 ° 20’

22. 𝑑𝑖𝑓𝑓𝑒𝑟𝑒𝑛𝑐𝑒 𝑖𝑛 𝑙𝑎𝑡𝑖𝑡𝑢𝑑𝑒𝑠 = 𝑃 𝑙𝑎𝑡𝑖𝑡𝑢𝑑𝑒 + 𝑄 𝑙𝑎𝑡𝑖𝑡𝑢𝑑𝑒
= 50 ° + 30 °
= 80 °
𝑄 (30 ° 𝑁,
160 ° 𝐸)
𝑃 (50 ° 𝑆,
160 ° 𝐸)
= 80 × 60
= 4,800
海里
=
4,800
6
= 800 𝑘𝑛𝑜𝑡