Answers to Homework Assignments for Chapter 1, Part I
How Many Degrees? | Wherever You Go, There You Are! | Working With Time Zones |
Investigation #19 | How Many Degrees | How Many Degrees (pages 13 - 13) |
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Time and Longitude Problems
1. Solve the following problems for Longitude:
15°W
135°W
30°E
45°E
75°E
2. What time is it in New York City (75° West) when:
9 p.m.
4 a.m.
1 a.m.
5:46 a.m.
12:24 a.m.
3. If you fly from New York City (75° West) westward on Tuesday, what day will you arrive in?
Wednesday
Tuesday
Wednesday
Wednesday
4. 10 p.m., Tuesday, 4/5, NYC (75°W) to LA (120°W), 8 hour flight.
75°W to 120°W, 120°W - 75°W = 45°
45°/15°/hr = 3 hr, Heading West = subtract time = -3hr
10 p.m. Tuesday, 4/5 - 3hr = 7 p.m.. Tuesday, 4/5
7 p.m.. Tuesday, 4/5 + 8 hr (flight) = (7 p.m. to midnight = 5 hours, with 3 left over)
= 3 a.m. . Wednesday, 4/6
5. 10 a.m., Wednesday, 3/7, San Francisco (120°W) to Japan (135°E), 10 hour flight.
Method #1:
120°W to 135°E, 120°W to 0° =120°, 0° to 135°E = 135°, 120° + 135° = 255°
255°/15°/hr = 17 hr, Heading East = add time = +17hr
10 a.m., Wednesday, 3/7 + 17hr = (10 a.m. to noon = 2 hr, noon to midnight = 12 hr)
= 2hr + 12hr = 14hr. 17hr - 14hr = 3 hours left over
= 3 a.m., Thursday, 3/8
3 a.m., Thursday, 3/8 + 10 hr (flight) = (3 a.m. to noon = 9 hours, with 1 hr left over)
= 1 p.m., Thursday, 3/8
Method #2:
120°W to 135°E, 120°W to 180° = 60°, 180° to 135°E = 45°, 60° + 45° = 105°
105°/15°/hr = 7 hr, Heading West = add time = -7hr
Crossing the International Date Line (180°) to the West = +1 day, Wednesday, 3/7 becomes Thursday, 3/8
10 a.m., Thursday, 3/8 - 7hr = 3 a.m., Thursday, 3/8
= 3 a.m., Thursday, 3/8
3 a.m., Thursday, 3/8 + 10 hr (flight) = (3 a.m. to noon = 9 hours, with 1 hr left over)
= 1 p.m., Thursday, 3/8
10 p.m.
11:00 or 11 a.m.
12:00 or 12 p.m. or noon
Hawaii (starts at 150° West) = 17:00 or 5 p.m.
The Galapagos Islands (starts at 90° West) = 6 a.m.
What Time Is It? (pages 13 - 14)
- 6 a.m.
- 6 a.m.
- 3 p.m.
- 1 p.m.
- 10 p.m.
- 2 a.m.
- 12 p.m.
- 3 p.m.