Question

Until 1883, every city and town in the United States kept its own local time. Today, travelers reset their watches only when the time change equals 1.0 h. How far, on the average, must you travel in degrees of longitude between the time-zone boundaries at which your watch must be reset by 1.0 h? (Hint: Earth rotates 360° in about 24 h.)

Short answer

Degrees of longitude traveled per hour is 15^o.

Step-by-step solution

Understanding the time zones and degrees

Time zones tend to follow national boundaries and subdivisions rather than strictly follow longitude. Time zones are based on how many degrees’ longitude the Earth moves in each hour.The Earth rotates in 24 hours.

Calculating the time zone traveled

The number of degrees corresponding to one hour is

$\raisebox{1ex}{${360}^o$}\!\left/ \!\raisebox{-1ex}{$24hr$}\right.={15}^o$

Therefore, the time zone traveled in degrees of longitude per hour is${15}^o$