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Tuesday, 7 November 2017

What Keeps The Earth in Constant Motion?


What keeps our earth in constant motion?
The Earth as a planet has kept everything on it in constant rotational motion and it seems it's never gonna stop moving. As a science lover, I feel dumbfounded when asked about what makes the earth turn(rotate). Did it start a long time ago and it just keep turning or s something pushing it to turn? How does the earth continue to rotate around its axis and if this is so, where does the energy to keep it moving come from? Answers to these questions lies in our understanding of the solar system that we belong which is being manned by a star-the SUN. The sun lies at the heart of the solar system where it is by far the largest object and it is known that the earth revolves round it, but why? The sun is 109 times the diameter of the earth(12800km)-about one million earths could fit inside the sun. The visible part of the sun burns at approximately 6000 degrees Celsius, while the temperature in the core reach more than 15 million degrees Celsius, driven by nuclear reactions, making one of the 100 billion stars in the milky way. Just like most other stars the sun is made up mostly of hydrogen followed by helium and the remaining mass consists of seven other elements-oxygen,carbon,neon,nitrogen,magnesium,iron and silicon. Hydrogen accounts for roughly 72% of the sun's mass while helium makes up about 26%. The gravitational acceleration of the sun is far more greater than that of any planet in the solar system including the earth and this makes the sun exert a pull force on all of the planets surrounding it. The earth tends to move away from this pull as a means of escaping from such pull, which makes for the circular motion it undergoes. Be it as it may, our everyday experience tells us that an object must be pushed by a force in other to keep it moving otherwise it will slow down and eventually stop, that is if the body is on earth
but this not the case in the solar cycle. I think if an object is at rest or moving, then a force is needed to slow it down or stop it-not to keep it moving. Which means that objects in motion tends to be in motion and objects at rest tends to remain at rest. Friction-the force that exists between two surfaces in contact tending to oppose the motion of one over the other-tends to stop earth-bound objects from moving forever. But for the earth rotating on its axis,there is no force working to counteract the rotation,so it doesn't need to have any input energy to keep it rotating. I think what started the rotating in the first place has to be it's angular momentum-the tendencies of things to rotate-a basis for its formation. The earth was formed out of a nebula that collapsed of which thereafter it began to rotate. Angular momentum of the earth is proportional to the moment of inertia and angular speed. Moment of inertia is dependent on the position of the axis of rotation and the shape of the matter while angular speed occurs about a centre of rotation. Thus the earth's rotation will continue for the next 5 billion years until the sun dies. Watch out for more articles by me.

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