Chapter 3 Flashcards
How long does it take for the earth to rotate 360 degrees?
24 hours
How long does it take the earth to rotate 15 degrees
1 hour
How long does it take the earth to rotate 1 degrees?
4 mins
What does LMT stand for?
Local Mean Time
If a meridian is East of an observer is it ahead or behind the LMT?
Ahead
If a meridian is West of an observer is it ahead or behind the LMT?
Behind
How much does the earth turn every minute?
15’
1degree divided by 4
1 degree = ? Minutes
4 minutes
1’ = ? Seconds
4 seconds
Standardised time is where…
Clocks in a geographic region are synchronised
What does UTC stand for?
Universal time coordinate
BMT means?
British Mean Time
If British Mean Time has a 0 UTC offset then what is British Summer Time?
UTC+1 (daylight savings)
What is the international dateline?
When you cross it the date changes
If you cross the international dateline east to west what happens?
You subtract a day
If you cross the international dateline west to east what happens?
You add a day
If two places have a UTC offset of UTC -10 and UTC +13 what is the time zone difference?
+/- 23 hours (depending on which way you go)
When is sunrise?
When the upper limb of the sun appears on the horizon
When is sunset?
When the upper limb of the sun disappears below the visible horizon
When is sunlight?
Between sunrise and sunset
What is the suns upper limb?
The first or last visible part of the sun
What is twilight?
The incomplete light before sunrise or sunset
When is civil twilight?
From sunrise/ sunset until the suns upper limb is 6 degrees below the horizon
How many degrees does the earth rotate per hour?
15 degrees per hour
