Question

Find out the time at 15 degree East and at 30 degree west if the time at zero degree longitude is 10 am Monday?​

Answer 1

Explanation:

1 degree equals 4 minutes.

According to the question, the time at 90 degree East longitude is 11 am, and to reach 15 degree west longitude it will have to go 105 degrees east as first of all it will go to 0 degree and then 15 degree to reach 15 degree west longitude.

1 degree = 4 minutes

105 degree = 105×4= 420 minutes

420÷60= 7 hours

We know that by moving from East to West, time decreases. So, we will have to subtract 7 hour from 11am to know the time at that place.

Therefore, 11am - 7hr= 4 am

So, the time will be 4am at 15 degree west longitude if the time is 11am at 90 degree East longitude

Hope it helped you

Answer 2

Originally Answered: If it is 12 noon at 60 degrees East, then what will be the time at 30 degrees West longitude?

Solution:

Step 1. The earth takes 4 min to rotate through 1 degree of longitude.

Hence, the earth will take 240 minutes to rotate through 60 degrees of longitude ( 60×4)

Or the earth will take 4 hours to rotate through 60 degrees of longitude. ( 240/60)(since 1 hour=60 minutes).

Thus, we can say that the difference in time between the places lying on 60 degree east longitude and prime meridian(0 degree) is 4 hours.

Step 2: as the prime meridian lies towards the west of 60 degree east longitude, so the GMT will be 4 hours behind to the local time at 60 degree east longitude i.e. 8A.M in the morning.( 12P.M _ 4 hours)

Step3: now we need to find the difference in time between the places lying on 30 degree west longitude and prime meridian i.e.( 30×4=120 minutes or 2 hours( 120/60).

Hence, the time difference between places lying on prime meridian( 0 degree longitude) and places lying on 30 degree west longitude is 2 hours.