Satellite motion
Projectile motion - satellites
In the previous section we have seen that a projectile will follow a very predictable curved path in air.
However when the projectile is given a greater speed, it goes further.
The reality of the situation is that the Earth is curved.
So what happens if you fire a projectile and it goes over the horizon?
It will probably land further away.
So what happens if you increase the speed some more?
Now the projectile is so fast it will travel so far forward that by the time it drops, the Earth will have curved away.
This is the start of satellite motion.
If the projectile has enough speed, it will move through space constantly falling towards the Earth in falling freely in space / air, not attached to anything. Eg: the skydiver was in freefall after leaving the plane.. With the high horizontal speed – constant horizontal speed – the projectile falls around the The slight bending of the horizon due to the roundness of the Earth, more noticable at higher altitudes, eg the curvature of the Earth can be seen from the International Space Station. of the Earth.
The higher the satellite, the longer it takes to orbit.
The International space station orbits at an altitude of approximately \(350km\)and takes just about 90 minutes to orbit the Earth.
A A satellite orbiting a planet at the same rate as the planet. A geostationary satellite orbiting Earth has a period of 24 hours. communications satellite orbits at an altitude of \(36,000km\) taking 24 hours to orbit the Earth. This means that it will stay above the same geographical location.
