Page 109 - text book form physics kssm 2020

Chapter 3
Gravitation
3.3 Man-made Satellites
Man-made Satellites

Orbit of Satellite
Figure 3.33 shows the International Space
Station, ISS, and MEASAT satellite. ISS can be International Space MEASAT
Station (ISS)
seen from the Earth because of its large size and
orbits at a height of 408 km. MEASAT satellite
is diffi cult to be seen because of its small size
and orbits at a height of 35 786 km. Satellites
move in orbits at specifi c heights and suitable
linear speeds.
Formulae for centripetal force and
Newton’s Universal Law of Gravitation are
used to establish and determine the linear
speed of satellites. Figure 3.34 shows the orbit
of a satellite around the Earth.
v
Figure 3.33 Man-made satellite orbiting the Earth
m
S S
Satellite
Satelit
M F
Position and path of ISS
Mass of the Earth = M
Mass of satellite = m
r Radius of orbit of satellite = r
Earth Linear speed of satellite = v
Orbital period = T
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Figure 3.34 Orbit of a satellite
A satellite moving in a circular orbit around the Earth experiences
centripetal force, which is gravitational force. CAREER
iNFO

Astronautical engineering
GMm
Gravitational force between satellite and the Earth, F = involves the fi eld of
r 2
mv 2 Physics on orbital
Centripetal force on satellite, F =
r mechanics, outer space
Centripetal force = Gravitational force environment, guidance
mv 2 GMm and control of height,
=
r r 2 telecommunications,
GM aerospace structure and
v =
2
r rocket propulsion.
GM
v =
r

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