What are geostationary and polar satellites?

Explanation

Geo-stationary and polar satellite:
(i) The satellites orbiting the Earth have different time periods corresponding to different orbital radii. Orbital radius of a satellite if its time period is 24 hours is calculated below:
Kepler's third law is used to find the radius of the orbit.
`T^(2) = (4pi^2)/(GM_E) (R_(E) + h)^(3)`
(R_(E) + h)^(3) = (GM_E T^2)/(4pi^2)`
`R_(E) + h = ((GM_(E)T^(2))/(4pi^2))^(1//3)`
(ii) Substituting for the time period (24 hrs = 86400 seconds), mass and radius of the Earth, h turns out to be 36,000 km. Such Satellites are called "geo-stationary satellites", They appear to be stationary when seen from Earth.
(iii) Geo-stationary satellites is used for the purpose of telecommunicatio. Another type of satellite which is placed at a distance of 500 to 800 km from the surface of the Earth orbits the Earth from north to south direction.
(iv)This Type of satellite which orbits Earth from North Pole to South Pole is called a polar satellite.
(v) The time period of a polar satellite is nearly 100 minutes and the satellite completes many revolutions in a day.
(vi) A polar satellite covers a small strip of area from pole to pote during one revoluation. In the next revoluation, it covers a different strip of area since the Earth would have moved by a small angle.
(vii) In this way polar satellites cover the entire surface area of the Earth.