Understanding Time Zones
When determining the time in a city based on its longitude, it is important to understand how the Earth's rotation affects time zones. The Earth is divided into 24 time zones, each generally covering 15 degrees of longitude.
Prime Meridian Time
- The Prime Meridian (0° longitude) is the starting point for measuring time.
- When it is 8:00 a.m. at the Prime Meridian, this time is referred to as Coordinated Universal Time (UTC).
Calculating Time Difference
- The Earth rotates 360 degrees in 24 hours, which means it rotates 15 degrees per hour.
- For each degree of longitude east or west of the Prime Meridian, the time changes by 4 minutes.
Longitude of 30° East
- A location at 30° east is 30 degrees away from the Prime Meridian.
- To find the time difference, calculate: 30 degrees × 4 minutes = 120 minutes.
- This translates to 120 minutes = 2 hours.
Time in the City
- Since the city at 30° east is ahead of the Prime Meridian, we add the 2-hour difference.
- Therefore, if it is 8:00 a.m. at the Prime Meridian, we add 2 hours to find the local time.
Final Result
- 8:00 a.m. + 2 hours = 10:00 a.m.
In conclusion, when it is 8:00 a.m. at the Prime Meridian, it is 10:00 a.m. in a city located at 30° east longitude.