Physics - September 2006

Find speed of a satellite which orbits the moon near moon's surface?What is the kinetic energy per unit mass of the satellite?
My workings are Fc(centripetal force)=Fg(gravitational force) so v=(GM/r)^(0.5)= 1680 m/s I got this correct but I took kinetic energy per unit mass of the satellite equals to gravitational field strength which is X=(GM/r) = 2.42x10^6 is my thinking correct? but the answer is 1.41x10^6J/kg.
Details given are radius of moon=1.74x10^6 m and mass of the moon=7.35x10^22 kg

Another extra unrelated question is that if the assumption is that gravitational potential at the surface of the earth to be zero, can we use the equation F=GMm/(r)^2?? Whats the meaning of the assumption? we use Energy=mgh instead??? Eg to find the gravitational field strength at p what do we do?????????

2006-09-16 03:42:45 · 4 answers · asked by Big bird 1

2006-09-16 03:38:10 · 3 answers · asked by Annie 1

How far from the sun would the light rays converge?

2006-09-16 03:29:21 · 1 answers · asked by goring 6

Would the volume be bigger or smaller ?

2006-09-16 03:25:43 · 9 answers · asked by goring 6

2006-09-16 03:01:30 · 8 answers · asked by goring 6

I do not mean the volume of an object. I am talking about the objects shape (square, sphere, etc.). How does on objects shape effect its density?

2006-09-16 02:50:57 · 5 answers · asked by Br 3

2006-09-16 02:48:44 · 18 answers · asked by Anonymous

Astronomical observations show that the centre of mass of the earth moon system is 4.7x10^6 from the centre of the earth. The distance between the centres if the earth and moon is 384.4x10^6. I don't know whether it means that the gravitational potential at this so called centre of mass of the system is zero or what is the question meaning in saying that the centre of mass of the system , how does it help , what does it imply?

2006-09-16 02:47:31 · 3 answers · asked by Big bird 1

When I look up the term "grain size" in wikipedia it says this: "Grain size refers to the physical dimensions of individual particles of rock or other solid". What does particle mean in this context?

2006-09-16 02:39:16 · 1 answers · asked by button 1

2006-09-16 02:27:42 · 16 answers · asked by Senthil 3

2006-09-16 01:58:03 · 3 answers · asked by yaradua1908 1

2006-09-16 01:53:01 · 7 answers · asked by Anonymous

2006-09-16 00:33:29 · 2 answers · asked by gen 2

2006-09-16 00:08:26 · 8 answers · asked by tuugud 1

2006-09-15 23:56:10 · 6 answers · asked by Anonymous

why is it usually taken at the brachial artery andnot on the artery in the leg?

2006-09-15 23:42:43 · 3 answers · asked by jaw_fil 1

could they pass through an object by avoiding a collision on a sub atomic level. I know it's a far out idea, but if you could would it be possible?

2006-09-15 23:40:04 · 5 answers · asked by myxodo05 1

I was watching Syriana in which a swimming pool light has failed so the water is charged with electricity. This is analogous to when people drop toasters in swimming pools. The thing is that I would have thought the electricity would take the easiest route to earth, which would only be you if you were still touching the sides and the pool was insulated from earth itself. So why does the electricity travel through the higher resistance material (the body)?? Or if it doesn't, how does it kill people??

2006-09-15 23:37:17 · 12 answers · asked by fearsome_gibbon 3

please help!!! this is all about buoyant force, Physics.

2006-09-15 23:36:00 · 14 answers · asked by jaw_fil 1

The arctic ice cap is as far as i am aware mainly free floating. Therefore, the volume of water displaced is equivalent to the weight of ice sitting on it. The density of ice is lower hence it floats and its volume is greater would it not be a zero sum result. Just how much would a total melt down actually raise sea levels.
The Antarctic is a different kettle of fish!!

2006-09-15 23:33:09 · 11 answers · asked by mikki finn 2

alternative products use for killing pests

2006-09-15 23:13:06 · 2 answers · asked by Anonymous

complete the following sentence

2006-09-15 23:02:43 · 7 answers · asked by wessam a 1

Hi all! I've got a question on capacitance.
For resistors in series, the rule is that the higher the resistance of an appliance, the higher the potential difference across it.
What about capacitors in series? Is it the higher the capacitance of a capacitor, the lower the potential difference across it?

2006-09-15 22:22:55 · 3 answers · asked by Anonymous

I know that at the "start"of the BIG BANG no cesiumatom existed.So "time"could not be expressed,certainly not by an atomoscillation.The reason of my question was that often I read:"one second (or one minute,hour,etc)after the beginning of the BIG BANG..." What is the meaning of such a statement?And when the first cesiumatom was born I suppose that "matter"was still extreme dense.I presume that 1 oscillation of that atom "then"would have been many oscillations of an cesiumatom in "ANOTHER WORLD"where there also have been a"BIG BANG" but very very earlier". RESUMED:"1 second,minute,etc"When I read such a statement in a "scientific"article I become puzzled.Please answer only seriously.(Jokes I know enough)

2006-09-15 22:05:08 · 9 answers · asked by Anonymous

2006-09-15 21:28:09 · 6 answers · asked by GOOCH 4

Why both Earth and moon must rotate about the common centre of mass rather than the moon about the centre of mass of Earth?

Intro: Astronomical observations show that the centre of mass of the earth moon system is 4.7x10^6from the centre of the earth.

2006-09-15 20:43:59 · 7 answers · asked by Professor X 1

2006-09-15 19:35:32 · 10 answers · asked by Smoky 3

2006-09-15 18:16:21 · 21 answers · asked by aonnoy_sengupta2000 1

I need to do a project on physics ......and i haven't found even one.
i prefer cbse level projects for 12th class........help please

2006-09-15 17:57:28 · 2 answers · asked by dya 1

You know, as Einstein said, all energy has an equivalent mass - E equals em cee squared and all that. So each object should carry, besides its own mass, the little bundle of mass equivalent to its gravitational energy.

2006-09-15 17:45:38 · 11 answers · asked by Problem Child 2