How much does the Earth rotate in longitude every hour?

The Earth rotates 360° in a full 24-hour period. To determine how much it rotates in one hour, you can divide 360° by 24 hours. This calculation shows that the Earth rotates 15° of longitude every hour.

This rotational rate is essential for understanding time zones, as each time zone typically represents a 15° change in longitude, corresponding to a one-hour difference in local time.

The other options do not accurately represent the Earth's hourly rotation in degrees of longitude. For instance, 30° would imply a much faster rotation rate, while 45° would suggest that the Earth rotates over a much shorter time span than one hour. An option of 1° significantly underestimates the movement, as it would mean only a fraction of an hour's rotation. Thus, knowing that the Earth rotates 15° every hour is crucial for both timekeeping and navigating based on longitude.