Question

if the time is 3.00 pm at 45°e longitude what will be time at 105° E longitude​

Answer 1

The time will be 7:00pm at 105°E longitude because the time differs 1 hours for every 15°

since105-45=60°,60/15=4

so, 3+4=7:00pm

Answer 2

Given :-

The time is 3:00 pm at 45° E Longitude

Required to find :-

• Time at 105° E longitude

Solution :-

Before solving this question we need to know some important concept regarding this topic .

The 0° longitude is the Prime Meridian or Greenwich Meridian .

Since, the Britain were first to draw the first accurate maps using latitudes and longitudes .

They consider the longitude passing through the England as the 0° longitude .

The time taken by the sun rays to fall on one longitude is 4 minutes .

However, The time is considered to be added up till the anti-meridian . 180° longitude is considered to be as Anti-Meridian .

The time is considered to be subtracted once it crosses 180° longitude .

This states the fact that when it is 12:00 PM at England it will be 12:00 AM at Anti-Meridian .

Using this concept let's solve the Question ;

Given information :-

The time is 3:00 PM at 45° E longitude .

we need to find the time at 105° E longitude .

The no. of longitudes in the between these 2 places is ;

105 - 45

60

Since,

The time taken by the sunrays to fall on 1 longitude is 4 minutes

This implies ;

If two places have a difference of 1 longitude then they considered to have 4 minutes time difference .

So,

60 longitudes =

=> 4 x 60

=> 240 minutes

we know that ;

60 minute = 1 hour

240 minutes = ? hrs

=> 240/60

=> 4 hours

Hence,

The time diffrence between the 45° and 105° is 4 hours .

So,

At 45° E longitude the time is 3:00 PM

At 105° E longitude the time is 4 hours ahead of 45° E longitude .

Thus ,

3:00 pm + 4 hrs = 7:00 pm

Hence,

Time at 105° E longitude is 7:00 pm .

Points to remember :-

1. The time taken for sunrays to fall on each longitude is 4 minutes .

2. 0° longitude is Greenwich Meridian or Prime Meridian .

3. The word " Greenwich " is read as " Gren - ich ".

4. The time when calculated depends on 2 conditions if the longitude is more than 180° then the time difference needs to subtracted .

5. Similarly, if the longitude is less than or equal to 180° then the time difference needs to be added up .

These are the most important points to be remembered while solving these type of questions .