SATELLITE

by

Nokesh

Prabhakar

Satellite:- revolves around planet, Uniform velocity, fixed orbit

1.Artificial satellite

• Ex-polar satellite

2.Natural satellite

• Ex-moon

Satellite are of two types:-

Natural Satellite:- A Natural Satellite is a Natural Body which revolves around(orbits) a Planet .It is usually called moon and is large and ball shaped.

There are 177 natural satellite in our solar system.

Mercury-0Venus-0Earth-1Jupiter-67Saturn-62Uranus-27Neptune-13Mars-2Pluto-5

Artificial Satellite:-A Artificial Satellite is an object which has been placed into orbit by human endeavour.

Sputnik 1 –launched by Soviet union in 1957.

Artificial Satellite is of two types :-

1..Geostationary Satellite

2. Polar Satellite.

Geostationary Satellite

1.Rotates around the Earth over equator2.Fixed over a particular place3.40,000 km above the Earth surface4.Time period is 24 hours5.Used in telecommunication

Polar Satellite

1.Rotates around the Earth from pole to pole2.Rotate around the Earth 8-10 times per day3.Only 300-400 km above the earth surface4.Time period is 2-3 hours5.Used in weather broadcasting ,remote sensing and G.p.s

Escape Velocity of a Satellite:- maximum speed to which a object is projected so that it moves out of gravitational field .

Luna 1

The escape velocity of a satellite is

Location

with respect to

Ve[2]     Locatio

n

with respect to

Ve[2]

on the Sun,

the Sun's gravity:

617.5 km/s

on Mercury,

Mercury's gravity:

4.3 km/s

at Mercury,

the Sun's gravity:

67.7 km/s

on Earth,

the Earth's gravity:

11.2 km/s

at the Earth/Moon,

the Sun's gravity:

42.1 km/s

on the Moon,

the Moon's gravity:

2.4 km/s at the Moon,

the Earth's gravity:

1.4 km/s

on Mars, Mars' gravity: 5.0 km/s at Mars,

the Sun's gravity:

34.1 km/s

on Jupiter,

Jupiter's gravity:

59.5 km/s

at Jupiter,

the Sun's gravity:

18.5 km/s

on Saturn,

Saturn's gravity:

35.6 km/s

at Saturn,

the Sun's gravity:

13.6 km/s

on Uranus,

Uranus' gravity:

21.2 km/s

at Uranus,

the Sun's gravity:

9.6 km/s

on Neptune,

Neptune's gravity:

23.6 km/s

at Neptune,

the Sun's gravity:

7.7 km/

on Pluto, Pluto's gravity: 1.2 km/s

in the Solar System,  

the Milky Way's gravity:   ≥ 525 km/s[3]

on the event horizon,  

a black hole's gravity:   = 299,792 km/s

Orbital Velocity:- velocity at which an satellite rotates around a planet.

Orbital velocity of a satellite

Relation between orbital velocity and Escape velocity

=√gr

Time Period of a satellite:- time taken by a satellite for 1 revolution.

The time period of a satellite

T=2∏r×√r √GM

Height of a satellite:- the expression to find out height of satellite is

Total Energy of a satellite :-Kinetic energy of a satellite=

Potential energy of a satellite=

Total energy of a satellite= K.E-P.E

GMm 2r

-GMm r =GMm -

GMm 2r r =-GMm 2r

Kepler‘s law of Elliptical orbit

According to kepler’s 1st law the orbits of all planets are elliptical and sun remains at one of the focus

Kepler’s law of aerial velocity

According to kepler’s 2nd law , a planet covers equal area in equal interval of time.

Kepler’s law of time period

According to kepler’s 3rd law ,square of the time period is directly proportional to the cube of the semi-major axis.

T² r³