1. Latitude is an angle (defined below) which ranges from 0° at the Equator to 90°
(North or South) at the poles. Lines of constant latitude, or parallels, run east-
west as circles parallel to the equator. Latitude is used together with longitude to
specify the precise location of features on the surface of the Earth.
Longitude-is a geographic coordinate that specifies the east-west position of a
point on the Earth's surface. It is an angular measurement, usually expressed
in degrees and denoted by the Greek letter lambda (λ). Points with the same
longitude lie in lines running from the North Pole to the South Pole. By
convention, one of these, the Prime Meridian, which passes through the Royal
Observatory, Greenwich, England, was intended to establish the position of zero
degrees longitude. The longitude of other places was to be measured as the
angle east or west from the Prime Meridian, ranging from 0° at the Prime
Meridian to +180° eastward and −180° westward. Specifically, it is the angle
between a plane containing the Prime Meridian and a plane containing the North
Pole, South Pole and the location in question. (This forms aright-handed
coordinate system with the z axis (right hand thumb) pointing from the Earth's
center toward the North Pole and the xaxis (right hand index finger) extending
from Earth's center through the equator at the Prime Meridian.)
The Equator usually refers to the Earth'sequator: an imaginary line on the
Earth's surface equidistant from the North Pole and South Pole, dividing the
Earth into the Northern Hemisphere and Southern Hemisphere.
A prime meridian is a meridian (a line of longitude) in a geographical
coordinate system at which longitude is defined to be 0°. A prime meridian and
its opposite in a 360°-system, the 180th meridian (at 180° longitude), form a
great circle. This great circle divides the sphere, e.g., the Earth, into two
hemispheres.
Inertia is the resistance of any physical object to any change in its state of
motion, including changes to its speed and direction. It is the tendency of objects
to keep moving in a straight line at constant velocity. The principle of inertia is
one of the fundamental principles of classical physics that are used to describe
the motion of objects and how they are affected by applied forces. Inertia comes
from the Latin word, iners, meaning idle, sluggish. Inertia is one of the primary
manifestations of mass, which is a quantitative property of physical
systems. Isaac Newton defined inertia as his first law in his Philosophiæ
Naturalis Principia Mathematica, which states:[1]