Question

Workings of what will be the local time in Nigeria (longitude 15°) if the local time is 10pm in Ethiopia (longitude 45°)

Answer 1

To determine the local time in Nigeria (longitude 15°) when it is 10 PM in Ethiopia (longitude 45°), we need to consider the time difference based on their longitudes.

The Earth is divided into 360 degrees of longitude, and it takes 24 hours for the Earth to complete a full rotation. This means that each degree of longitude corresponds to 4 minutes of time (360 degrees / 24 hours = 15 degrees per hour).

Now, let's calculate the time difference based on the longitudes:

1. **Longitude of Ethiopia**: 45°
2. **Longitude of Nigeria**: 15°

The difference in longitude between Ethiopia and Nigeria is:

\[
45° - 15° = 30°
\]

Next, we convert this angular difference into time:

Since each degree corresponds to 4 minutes, we calculate the time difference:

\[
30° \times 4 \text{ minutes/degree} = 120 \text{ minutes}
\]

120 minutes is equivalent to 2 hours.

Now, since Ethiopia is to the east of Nigeria, we subtract the 2 hours from the local time in Ethiopia to find the local time in Nigeria:

Ethiopia's local time: 10 PM
Subtract 2 hours:

10 PM - 2 hours = 8 PM

Thus, when it is 10 PM in Ethiopia, it will be **8 PM in Nigeria**.