SSSalvi wrote:^^^

M=7.35*10^22

GM=49000

R=1738+10

V= 5.3 km/sec

This is going OT I think, so this is my last post on this.

What's going on, madrasa math?

Here's the universal gravitational constant, G:

https://en.wikipedia.org/wiki/Gravitational_constantThe value is: 6.6734e-11 in SI units.

So how in the world did GM, with M=7.35e22 kg, become 49000

What units are these in? Certainly not SI.

Here's the escape velocity of the moon:

https://en.wikipedia.org/wiki/Escape_velocityScroll down that wiki link, you will find escape velocity on the moon being 2.38 km/s. So your number of 5.3 km/s is more than twice this

Meaning if you go at this speed, you are going to fly off the moon and never come back. Certainly not orbit the moon at any height.

My radius was a little wrong, but even with the value which you have (which is right, thanks for the correction), I get 1.674 km/s at a 10 km height, and 1.633 km/s at 100 km height above the moon.

Again, my last post on this.

EDIT: (Ah I see - your value of G is off by a factor of 100 million, and you forgot to convert the radius from km to metres).

FURTHER EDIT (Don't wan't to prolong this OT discussion, so I'm editing my previous post instead of doing a new post):

SSSalvi wrote:^^^

^^^

My Apologies.. Sudarshan , for the post.

SSSalvi, didn't mean to be harsh, just that two of my pet peeves got touched off:

1. Reporting physical constants or properties of objects as numbers is meaningless, unless units are included - for ex., is the reported mass in grams, kg, pounds... is the reported radius in metres, km, miles... etc. Especially with some number like G (universal gravitational constant) units are critical. In your post, I strongly suspect that mismatched units are what messed up the final result.

2. When possible, always perform a sanity check after any calculation. In this case, one calculation reported an orbital velocity for the moon greater than the escape velocity of Jupiter(!), and another one reported 2.5 times the escape velocity of the moon! These escape velocity numbers can be readily looked up, and serve as sanity checks - they would have instantly shown that the reported orbital velocity numbers could not be true.

Sorry if I sounded like I was ranting.