Why nautical mile is different from statute mile?
One nautical mile is defined by one latitude minute of arc (there are 60 such minutes to a degree). This equals 1852 meters, and roughly (but coincidentally) 2000 yards or 6000 feet. (Edit: actually, a standard nautical mile is 6076 feet, 6000 feet and 2000 yards are commonly used approximations, but produce an error of about 1%). The statute mile had a little fuzzier definition to start with, as one mile was the same as 1000 roman PAces/steps. The definition has since changed, but one statute mile equals about 1609 meters. What is rigging? In sailing, the ropes used to move the sails around so the boat will move in the right direction when the wind blows. What is absolute pressure? Absolute pressure is simply the addition of the observed gage pressure plus the value of the local atmospheric pressure. How do you calculate absolute pressure? Absolute is equal to gauge pressure plus atmospheric. What is Gravity flow? Gravity flow is fluid flowing due to the forces of gravity alone and no