satellites,orbital velocity ,escape velocity

1. Satellites
Josly Jose
P.K. M. College of Education

2. SATELLITES
• The body revolving around a planet in a fixed
orbit is called a satellites
• The natural satellites of earth is moon
• Example for artificial satellite are Sputnik,
Aryabatta, INSAT etc

3. Natural satellite Artificial satellites

4. ORBITAL VELOCITY
• Orbital velocity of a satellite is the
velocity with which is revolves round
a planet in its fixed orbit. orbital
velocity is denoted by VO

5. Expression for orbital velocity
• Consider a satellite of mass ‘m’ that revolves round the
earth in an orbit of radius RE+h, with velocity VO.
The centripetal force required for revolution is given by,
FC =
Gravitational force between earth and satellite ,
Fg =
=

6. vo =
at the surface of earth , R+h = R
vo =
vo =

7. Relation between orbital velocity
and escape velocity
• Equation of orbital velocity
vo =
• Equation of escape velocity
Ve =
Ve = vo

8. The time period of a satellite
• The time taken by a satellite to complete to
complete one orbital motion around a planet is
called time period of a satellites
• Time period =
T =

9. The energy of an orbiting satellite
• The kinetic energy of the satellite in a circular
orbit with orbital velocity VO is
K E = ½
P E = -
T E = KE+ PE = -½

10. Activity
• Starting from the expression for period
of revolution of a satellite, prove
Kepler’s third law

11. THANK YOU