- #1

I'm looking for the formula to determine accureate value of g when value of longitude and height above sea level are given.

If you know if would be helpful if you could post a site that has the formula. (Want to have it as a reference).

Thanx!

You are using an out of date browser. It may not display this or other websites correctly.

You should upgrade or use an alternative browser.

You should upgrade or use an alternative browser.

- Thread starter Tawcan
- Start date

- #1

I'm looking for the formula to determine accureate value of g when value of longitude and height above sea level are given.

If you know if would be helpful if you could post a site that has the formula. (Want to have it as a reference).

Thanx!

- #2

chroot

Staff Emeritus

Science Advisor

Gold Member

- 10,275

- 40

Here's one page that may help:

http://www.npl.co.uk/pressure/faqs/altgrav.html

In general, you know Newton's law of universal gravitation:

F = G M m / r^2

and you know Newton's second law of motion:

F = m a

so you can substitute and solve for a:

a (g) = G M / r^2

Plug in the Earth's mass for M and your distance from its center as r. Voila. This calculation, of course, does not include the small effect of the rotation.

- Warren

- #3

Ambitwistor

- 841

- 1

Originally posted by Tawcan

I'm looking for the formula to determine accureate value of g when value of longitude and height above sea level are given.

Do you want a theoretical prediction, assuming the Earth is a uniform rotating sphere, or do you want some kind of empirically-fit formula from measured data, taking into account all the irregularities in the Earth?

(By the way, do you mean latitude, not longitude?)

- #4

Oops you guys are right.

Yep that's exactly the formula I'm looking for! Thanx for your help! :)

Yep that's exactly the formula I'm looking for! Thanx for your help! :)

Share:

- Replies
- 2

- Views
- 612

- Replies
- 4

- Views
- 438

- Last Post

- Replies
- 2

- Views
- 703

- Last Post

- Replies
- 27

- Views
- 786

- Replies
- 6

- Views
- 3K

- Replies
- 36

- Views
- 3K

- Last Post

- Replies
- 7

- Views
- 1K

- Last Post

- Replies
- 4

- Views
- 736

- Last Post

- Replies
- 2

- Views
- 2K

- Last Post

- Replies
- 4

- Views
- 913