Solar System And Orbital Motion
Gbogbo ọrọ náà
Somewhere on the wall of a building near you there is a satellite dish, bolted into the brickwork, pointing at an empty patch of sky. Nobody adjusts it. Nobody tracks anything with it. It was aimed once, on the day it was fitted, and it has not moved since, and the pictures keep arriving. That only works because a machine the size of a minibus, thirty six thousand kilometres above the equator, is circling the planet at a speed chosen so precisely that from the ground it appears to be nailed in place.
This lesson is about why that speed had to be what it is, and why the engineers had no freedom to pick a different one. You will take an inventory of the solar system and learn to separate a planet from a moon, a dwarf planet from an asteroid and either of those from a comet, on size and on the shape of the path they follow. You will find out what actually holds a planet in its orbit, why an object going round a circle at a steady speed is nevertheless accelerating every second of the journey, and why a satellite in a low orbit is racing while one far out is dawdling. By the end you will be able to look at a job a satellite has to do and say how high it must fly and how fast it must travel to do it.
Ebumnobi
- The Earth is one of eight planets orbiting the Sun (a medium sized star), which together with other smaller objects (asteroids, dwarf planets, comets) and moons orbiting several planets, make up the solar system. Students should be able to describe the principal differences between planets, moons, the Sun, comets and asteroids in terms of relative size and motion.
- Our universe is made up of: thousands of millions of galaxies that are each made up of thousands of millions of stars; our Sun is one of thousands of millions of stars in our galaxy called the Milky Way.
- Planets orbit the Sun and a moon is a natural satellite of a planet. Artificial satellites orbit the Earth and can be in geostationary or low polar orbits.
- Gravity provides the centripetal force that keeps planets and satellites (both natural and artificial) in orbit.
- The force of gravity acts towards the centre of the orbit. This unbalanced force causes acceleration towards the centre of the orbit, changing the direction of motion of the body (its velocity) but not its speed. The equation for calculating centripetal force is not required.
- The centripetal force due to gravity decreases as the separation of orbiting masses increases, resulting in lower orbital speeds.
- At a particular separation of the masses, the centripetal force results in a particular orbital speed. To stay in a stable orbit at a particular distance, the planet or satellite moves at a particular speed. A change in orbital speed results in a change in orbital radius. Students should be able to explain the motion of moons and artificial satellites and be able to apply this to the design of satellite placing where the speed will determine the radius of the satellite’s final position.
Maapụ uche
E seela isiokwu a ka ị hụ otu echiche si ejikọta.
Mepee maapụ uche na ngwa
Akwụkwọ Ọmụmụ
Ndetu Nkuzi Zuru Ezu di na Ngwa Green Bridge
Nweta ngwa Green Bridge CBT na ekwenti gi ma o bu kompiuta maka ulo akwukwo IGCSE zuru oke: akwukwo ule ndi gara aga, usoro nyocha, eserese uche, kaadi omumu na nkuzi olu.
Nnyocha Ọmụmụ
Ekele diri gi maka imecha ihe karịrị na Solar System And Orbital Motion. Ugbu a na ị na-enyochakwa isi echiche na echiche ndị dị mkpa, ọ bụ oge iji nwalee ihe ị ma. Ngwa a na-enye ụdị ajụjụ ọmụmụ dị iche iche emebere iji kwado nghọta gị wee nyere gị aka ịmata otú ị ghọtara ihe ndị a kụziri.
Ị ga-ahụ ngwakọta nke ụdị ajụjụ dị iche iche, gụnyere ajụjụ chọrọ ịhọrọ otu n’ime ọtụtụ azịza, ajụjụ chọrọ mkpirisi azịza, na ajụjụ ede ede. A na-arụpụta ajụjụ ọ bụla nke ọma iji nwalee akụkụ dị iche iche nke ihe ọmụma gị na nkà nke ịtụgharị uche.
Jiri akụkụ a nke nyocha ka ohere iji kụziere ihe ị matara banyere isiokwu ahụ ma chọpụta ebe ọ bụla ị nwere ike ịchọ ọmụmụ ihe ọzọ. Ekwela ka nsogbu ọ bụla ị na-eche ihu mee ka ị daa mba; kama, lee ha anya dị ka ohere maka ịzụlite onwe gị na imeziwanye.
- Which of these objects orbits a planet rather than orbiting the Sun directly? A. A comet B. An asteroid C. A moon D. A dwarf planet Answer: C
- What provides the centripetal force that keeps the Earth in orbit around the Sun? A. Friction B. Gravity C. Magnetism D. Air resistance Answer: B
- A satellite moves around a circular orbit at a constant speed. Which quantity is changing? A. Its mass B. Its speed C. Its velocity D. Its distance from the centre of the orbit Answer: C
- Satellite X orbits the Earth at a radius of 7.0 x 10^6 m and satellite Y at a radius of 4.2 x 10^7 m. Which statement is correct? A. X travels faster than Y and takes less time for one orbit B. Y travels faster than X and takes less time for one orbit C. X and Y travel at the same speed D. X travels more slowly than Y and takes more time for one orbit Answer: A
- How does the orbit of a comet differ from the orbit of a planet? A. A comet's orbit is nearly circular and a planet's is highly elliptical B. A comet's orbit is highly elliptical and a planet's is nearly circular C. Both orbits are perfect circles D. A comet orbits a planet and a planet orbits the Sun Answer: B
Rue ajuju ndi a n'ime ngwa ahu
Rue ajuju ndi a n'ime ngwa ahu
Akwụkwọ A Na-atụ Aro
Meecha Ajụjụ Ule Ọmarịcha
Ị chọrọ ime ajụjụ ule ọmarịcha gbasara Solar System And Orbital Motion? Budata ngwa Green Bridge CBT iji nweta ajụjụ ule ọmarịcha na nyocha zuru ezu gbasara isiokwu a.
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