Question

What would be the time at Prime Meridian when a new day starts at 180° longitude?

Answer 1

Since the earth makes one complete revolution of 360° in 24 hours, that means it passes through 15° in one hour, that also means 1° in 4 minutes.

As you must know Earth rotates from west to east, so every 15° we go eastwards local time is advanced by 1 hour.

Likewise, if you go westwards, local time is retarded by 1 hour.

So, we can conclude that places east of Greenwich gain time as they see sun earlier, whereas places west of Greenwich see the sun later and lose time.

So, if we know GMT, to find local time, we merely have to add or subtract the difference in the number of hours from given longitude.

(Longitude is angular distance which is measured in degrees along the equator east or west of Prime meridian) to cut in short,basically these are vertical lines which pass through both poles.

Now, the answer of your question;

50° towards east..

East means advanced time.

Divide 50° in 3 parts of 15° each and remaining for easy calculation as you know 15° in longitude means 1 hour.

So, it would be

15°(15×4=60min=1hr)+15°(1hr)+15°(1hr)+ 5°(5°×4=20min)= 3 hours 20 minutes. ahead

i.e 12+3hr 20min=03.20 pm

(Note: as mentioned above 1° in 4 minutes, that's why to calculate how much time in 15°, I multiplied it by 4 )

I really hope you understand

Answer 2

The time at the Prime Meridian would be 12:00 PM (preceding date) when a new day starts (succeeding date) at 180° longitude.

Explanation:

• Prime Meridian itself is considered as the line of 0° longitude.
• It can be understood through a simple calculation that if the Earth goes round 360° in 24 hours, it covers and distance of 15° in one hour.
• The distance between 0° longitude (Prime Meridian) and 180° longitude is clearly 180 degrees.
• If we divide this angular distance of 180° by 15° (for Earth covers 15° in one hour), we would get the time taken by Earth to go from 0° longitude to 180° longitude.
• 180/15=12 (hours). Therefore, the time difference between the Prime Meridian and the 180° longitude would be 12 hours.
• Thus, when a new day starts (12:00 AM) at 180° longitude, the time at Prime Meridian would be 12:00 PM (preceding date).