If a clock on a ship indicates that it is 2:00 PM in its home port, while another clock on the ship indicates that it is 12:00 noon at the ship's present location, what is the difference in longitude between the ship's position and its home port?
A) The ship is 2 degrees east of its home port.
B) The ship is 2 degrees west of its home port.
C) The ship is 30 degrees east of its home port.
D) The ship is 30 degrees west of its home port.
E) The ship is 45 degrees west of its home port.

Question

Quizplus · Accepted Answer

If there is a two-hour time difference between the home port and the ship's current location, it means that the ship has travelled 2/24 (or 1/12) of the way around the Earth.

Since the Earth is divided into 24 time zones, each representing a 15-degree difference in longitude, we can calculate the ship's position by multiplying 15 degrees by the fraction of the Earth that has been travelled:

15 degrees/time zone x 1/12 = 1.25 degrees

Since the ship's clock is behind the home port's clock, that means the ship is to the west of the home port. Therefore, the ship is 1.25 degrees x 24 time zones = 30 degrees west of its home port.

If a Clock on a Ship Indicates That It Is