A plane leaves Brasilia at 11am on 31 December. The plane crosses 0° Meridian and reaches Vladivostok via New Delhi. Tell the local time, date and day at New Delhi and Vladivostok when plane leaves Brasilia.
Sun rises in the east and sets in the west. Thus sun moves from east to west as the earth rotates from west to east. Earth can be seen as a sphere of 360 ̊. Earth rotates this 360 ̊ in 24 hours.
Rotation of earth in 1 hour = 360/24 = 15 ̊
The plane takes off from Brasilia on 31 December, Sunday at morning at 11.00 AM. The longitudinal coordinates that determine the time of Brasilia are 47.52 ̊ W. The next stopover of the flight is New Delhi that has the longitudinal time zone in the coordinates 82.5 ̊ E.
The difference in longitude between Brasilia and New Delhi = 47.52 ̊ W + 82.5 ̊ E
= 130.02 ̊ E
Difference in time = 130.02/15 = 8.6 hours
= 8 hours + (0.6*60) minutes
= 8 hours 36 minutes (approx.)
Since the earth rotates from west to east, time zone at 82.5 ̊ E will be ahead of 47.52 ̊ W. Thus time would be lead in India by 8 hours 36 minutes.
Time in India when the flight takes off = 7.36 PM
The destination of the flight is Vladivostok that has the longitudinal time zone in the coordinates 131.88 ̊ E.
The longitudinal difference of Brasilia and New Delhi = 47.52 ̊ W + 131.88 ̊ E
= 179.4 ̊ E
Difference in time = 179.4/15 = 11.96 hours
= 11 hours + (0.96*60) minutes
= 11 hours 57 minutes (approx.)
Since the earth rotates from west to east, time zone at 131.88 ̊ E will be ahead of 47.52 ̊ W. Thus time would be ahead in Vladivostok by 11 hours 57 minutes.
Time in Vladivostok when the flight takes off = 10.57 PM