A
The orbital period of a geostationary satellite is ____ hours
24 hours
One benefit of high escape velocity of the Earth
1) Mantain a layer of atmosphere around the Earth
2) Aircrafts can fly at high levels without escaping into outer space
What is a satellite?
Any object that orbits another planet/star is known as a satellite.
Formula to calculate the linear speed of a satellite
Example of natural satellite
Moon - orbits the Earth
Earth - orbits the Sun
Geostationary satellite orbits in a special orbit named as _________ _________ Orbit
Geostationary Earth Orbit
Convert 11 200 m/s to km/h
40300 km/h
Escape velocity is the ___________ velocity needed by an object on the surface of the Earth to overcome the ________ force and escape to _________
minimum ; gravitational force ; outer space
Give 2 Movies / Stories about space and satellite
Bonus question
Star wars, Interstellar ...
Earth's escape velocity is ________ m/s
11,200 m/s
The factors that affect the Escape Velocity of a planet are ___________ and __________
1) The mass of the planet
2) Distance, r from the center of the planet
Why commercial aircraft cannot escape into outer space?
Commercial aircrafts can fly at linear speed of 250 m/s. The linear speed is lower than the escape velocity of the Earth
3 similarities of geostationary satellites and non-geostationary satellite
1) orbits the Earth
2) linear speed of the satellite, v
3) orbital period, T
3 uses of non-geostationary satellite
1. Earth imaging
2. GPS
3. Weather forecast
What happens when linear speed of satellite is less than required speed?
1) Satellite will fall to a lower orbit and continue to revolve towards the Earth until it enters the atmosphere
2) Against air resistance generate heat
3) Satellite burn up
The mass of spacecraft X is 1000 kg and the mass of scarecraft Y is 5000 kg.
Are the escape velocity from the Earth for spacecraft X different from spacecraft Y?
They are the same.
This is because the escape velocity, v of a planetary body does not depend on the mass of the object attempting to escape the gravitational pull of the planetary body.
Why do communication satellites need to be in geostationary satellite?
Communications satellites are often placed in a geostationary orbit so that earth-based satellite antennas (located on Earth) do not have to rotate to track them but can be pointed permanently at the position in the sky where the satellites are located.
- Always the same geographical location ;
- Orbit in Geostationary Earth Orbit ;
- Orbits at the equator (Angle of inclination = 0o)
How do we achieve Escape velocity?
Hint:
Minimum kinetic energy + Gravitational potential energy = 0
Escape velocity, v = ?
v = square root (2GM/R)
Calculate the Escape Velocity from the Moon
Given - Mass of the moon, M = 7.35 x 1022 kg
- Radius, r = 1.74 x 106 m
2.37 x 103 m/s
How to send a spacecraft into outer space?
- The launching of rockets requires large quantities of fuel
- To produce high thrust
- Enables the rocket to achieve escape velocity of the Earth