aswinramesh43: gud morn sir

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)