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# A Chat on Gravitation

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Please find an online chat with a class X student in an attempt to clarify his doubts on Gravitation.

 aswinramesh43: gud morn sir aswinramesh43 is online. MATHEW: good morning aswinramesh43: i didnt get any answer from u MATHEW: ? Which Question aswinramesh43: i have sent u 1 MATHEW: I am getting lot of questions everyday and I find it difficult to answer all instantly. If it’s urgent now, please ask now or give me the topic on which you asked aswinramesh43: i understand sir its not very urgent MATHEW: tell, I can look at it now. aswinramesh43: 1 min sir MATHEW: Because many questions are already answered at www.askphysics.com in one way or other aswinramesh43: every planet revolve around the sun . which force is responsible for that . an object cannot move without a force . MATHEW: OK aswinramesh43: this was my question MATHEW: I liked it and I was planning to answer it soon There are some basic things to remember An object moves in a straight line with uniform speed if no force is acting on it The planets move around the sun in circular (or elliptical) orbits, changing its linear path everytime because there is a force acting on it and the force which compells them to go in circular path is the GRAVITATIONAL FORCE aswinramesh43: does sun have the force ? MATHEW: Yes Evry body in this universe can exert Gravitational force aswinramesh43: but have any1 checked it out MATHEW: The planets moving around the sunb is the evidence There is no effect without a cause. aswinramesh43: hm MATHEW: The Gravitational force is UNIVERSAL The statement of the universal law of gravitation goes thus aswinramesh43: but other planets dont have it MATHEW: “Every object in this universe attracts every other object with a force which is directly proportional to product of their masses and inversely proportional to the square of distance between tem” All planets, stars,and even gas and dust have it. aswinramesh43: then why arent the astronouts going to other planets MATHEW: After the bigbang (which created the entire universe) the universe contained gallactic clouds of extremely light matter or gas. They were transformed into planets and stras because of GRAVITATION They are trying to go We went to moon and to mars Without gravitational force, how can someone enter into the surface of the planets. Please take it from me “Every object in this universe attracts every other object with a force which is directly proportional to product of their masses and inversely proportional to the square of distance between them” aswinramesh43: but in moon the gravitational force is just 1/6th of the earth MATHEW: Ya read the statement aswinramesh43: that was my qstn MATHEW: There are two thing The mass and the size aswinramesh43: i get it now MATHEW: A massive body will attract more aswinramesh43: yep 1 more qstn sir my physics mam has told that there no atmosphere around a star then how could it burn i mean we see it very bright and shiny ? MATHEW: Stars do have atmosphere but moon doesnot have because the average speed og gas molecules corresponding to the temp of moon is greater than the escape velocity (The minimum speed required for a body to escape from the surface of a body, a planet or a satellite)

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• Post Edited: Motion in one dimension Problem https://t.co/nIPbjtJim9
about 1 week ago