gravitation

Hello Harsha,

Your question was reapplied by Anonymous Hero yesterday in very good way in an another thread where you posed smiler question.

Think! Nothing can released from a stellite unless an external force is acted upon it and moment you apply a force on it, that body will scape from stellite until an equal amount of force is not applied on it in apposite direction.

The best answer to your question is text book. read ,read and read.

Here you can find the answer to your question provided you read it carefully many times.

i know that when net force is zero momentum is conserved accrdn to newton 2nd law.... so any body witot extrnal force remains at rest or mve wit cnstant velocity.... but a body released frm satelite is acted upon by a external force tatz the force with wich we throw the body.....( is it external or internal ??? .... ) so that body attains velocity with wich we throw and not the velocity of satelite na???? is my assumptions right??? if not tell me the correct ones .... i m very happy for the support u given to me in learning these concepts..... i request u to give me answers >>>. tanx for u r patience>> i m 12th class student...i m a slow learner ... try to understand

Your throw adds energy in the form of acceleration to the body. This acceleration is added to the velocity it had because it is traveling with you. The external force ceases as soon as your hand no longer is accelerating it. If you added enough velocity it might escape orbit, or if you threw it backward it would decelerate and descend into the planet. The sum of its final velocity after your throw is its initial velocity (same as satellite) plus however hard your throw is.

Newtons law states that a body ad rest tends to stay at rest and a body in motion tends to stay in motion. The 'at rest' state is only relative to its position. Picture a spaceship moving through deep space between galaxies. If you were to place an object 10 meters away, it would appear stationary, at rest and it would stay there until another force acts upon it. Relative to your starting planet you are both moving away toward your target, so you are both in motion. If you then accelerated your spaceship you would leave the object behind, but it would appear to accelerate away from you. You could only tell the difference by knowing that your velocity was being affected by your acceleration. So both the statements above are saying the same thing.

Drew

If this is a homework or school question, it has been suggested that we help with guiding questions if this is not such, let us know. It is not that I wouldn't want to help, it is just that I know that I learn better by searching and working for my answers.

If you understand what keeps a satellite in orbit, you should be able to figure this out too. They are both governed by Newtonian laws of motion, their speed, altitude, path of travel and attraction of gravity are all important to their orbital state.

I don't think I am very good at this sort of guiding, but will continue to help until you understand the concepts.

Drew

this is not a school question ..... itz my doubt i came across while solving problems of gravitation???? i m a 12th class student

I can best describe it by saying an object in orbit is falling toward the earth, but missing. Gravity is trying to accelerate the object toward the earth, but its angular velocity is causing its path to be a curve. Picture it as a ball on the end of a string you are swinging around your head. As you swing faster the pull you feel on the string increases. If you were the earth and the ball a satellite, the string would be gravity. When an object is in orbit the pull of gravity is equal to the pull you feel on the string swinging the ball around.

In orbital space there is not much that will influence your motion, not enough particles of dust or other materials to slow you. If you were on the space station and gently pushed off, you would continue in the direction you pushed yourself until something else affected your motion.

If you looked at it as a 3D model and you pushed yourself in one of 6 directions up and down being toward or away from earth, front and back being toward or away from the path of your orbit. A push upward or forward would result in a slight increase of your orbital speed and an eventual escape from orbit or an increase to a higher orbital location. A push down or back would result in descent to earth or a lower orbital location. A push of left or right would change the path of orbit slightly.

I hope this helps, ask more if it does not.

Drew

I think Newton, explained it best in his laws of motion.
I'll sumarise the first couple by saying...
Stuff doesn't move unless a force is acting on it.
If you leave stuff alone it will continue moving or not moving in exactly the same direction as it was.

A couple of simple experiments will demonstrate these laws, I suggest you do actually try them.

1. Sit at your desk quietly for a few moments and observe everything around you..
Right... were things jumping around randomly?
No? I didn't think so.

2. Next time you are in a car travelling along a smooth straight road at a steady speed. Sit quietly and observe the objects in the car (you can take your own object with you...an apple works well and can be eaten later). Hold the apple up in front of you on the flat of your hand.
Right... did the apple jump around randomly?
No? I didn't think so.

Right whilst in the car, if the vehicle suddenly brakes, what happens to the apple?
Did you say it shoots forward?
If you did you have failed and gone to the bottom of the class because you havn't observed carefully enough. (Observation is the key to experimentation)

The apple keeps moving forward... the car slows down. That's why the two move relative to eachother.
An observer at the roadside would see the apple continue in a straight path at a constant speed untill it hits something to stop it.
The car changed speed because the brakes were applied.
You changed speed because of your seatbelt and the friction between your backside and the seat
...the apple didn't change speed until a force was applied to it, probably by the windscreen or dashboard.

Del (that will be £5 please)

know that when net force is zero momentum is conserved accrdn to newton 2nd law.... so any body witot extrnal force remains at rest or mve wit cnstant velocity.... but a body released frm satelite is acted upon by a external force tatz the force with wich we throw the body.....( is it external or internal ??? .... ) so that body attains velocity with wich we throw and not the velocity of satelite na???? is my assumptions right??? if not tell me the correct ones .... i m very happy for the support u given to me in learning these concepts..... i request u to give me answers >>>. tanx for u r patience>> i m 12th class student...i m a slow learner ... try to understand

but a body released frm satelite is acted upon by a external force tatz the force with wich we throw the body.....

Slow down! Read your own posts carefully and try to understand the words.
Released is NOT the same as thow.

Yes, if you throw it then it will continue moving in the direction of the throw.
I don't think they throw satellites from space vehicles, they doubtless release them very slowly and carefully.
Del

Exactly Del, good point. Released the body would not move, it would stay in the same position. Released with a slight push is the same as a throw it would move in the direction and if that direction affected its orbit it could escape or descend.

Drew

Just an advice. try not to t_ext here.

Writing the whole word, clearly will have some added advantage.

It will improve your language.

As you write slowly you will understand what you are trying to convey and get the answer.

Quite a few old timers are allergic to the missing vowels (and some times whole syllables)

When net force is zero momentum is conserved according to newton 2nd law. Right

So any body without extrnal force remains at rest or move with constant velocity- I will just qualify it- It remains immobile with reference to the initial frame of reference.

But a body released from satellite is acted upon by a external force that's the force with which we throw the body- As del said, you do not throw them, you just release them from the vehicle.

So that body attains velocity with which we throw and not the velocity of satellite Isn't it?

Assume you throw the body, for whatever reason, try to look what happens. I will assume at the point of ejection, so that the other forces friction etc are not onto it. The body is thrown from where? the Launch Vehicle/Rocket. As the body is ejected from it, it attains a velocity with respect to its initial reference frame (what is that?)

(Assuming it has sufficient momentum, it will also disturb the mother). Look at the local picture and try to imagine the things exactly what is happening

Think of your own experiences. If you hang on the side of a moving car and step off, you continue to travel at the same speed until you hit the ground when friction is followed by a conversion of your linear motion to rotational motion as you tumble head over heels (I'm being very proper today).

This is as I remember from riding the running board of my Granddad's lorry, he never told us not to do it, but he wouldn't slow down for us to get off, either.

Give your experience as the guide for others? Maybe it works but we should know that there would be something inappropriate as we don't come across the same period.

Put astronaut in a box. Accelerate the box. Astronaut staying inside is accelerated with the box. At 1 M/sec or twice escape velocity, the astronaut is still inside the box with the same velocity as the box! Newton's first law says, paraphrased, that an object in motion or at rest remains at constant velocity unless acted upon by a force. What do you want a civil law?

Think man.

Luther M