Chapter 4.1, Problem 68E

Solution

To identify: The distance between Seattle and San Francisco them in nautical miles. assume that the two cities have the same longitude.

The distance between Seattle and San Francisco 587 nautical miles.

Given information:

The table is:

  

Explanation:

Consider the given information from the table, longitude position of Seattle is $47°36\text{'}$ and longitude position of San Francisco is $37°47\text{'}$ .

Hence the difference in longitude between the cities Seattle and San Francisco is

  $47°\text{ 36'}-37°47\text{'}$ .

Subtract the degrees from degrees and minutes from minutes with the subtraction of minutes first to obtain: $47°\text{ 36'}-37°47\text{'}=9°49\text{'}$ .

Thus, the difference in longitude between the cities San Diego and Los Angeles is $1°20\text{'}$

Since $1°=60\text{'}$ is 60 minutes so $9°47\text{'}=587$ minutes of arc. Since, 1 minute of arc of earth’s circumference is 1 nautical mile, so 587 minutes of arc is 587 nautical miles.