Calculating g Value with Longitude and Altitude: Formula and Reference

  • Context: Undergrad 
  • Thread starter Thread starter Tawcan
  • Start date Start date
  • Tags Tags
    Gravity Value
Click For Summary
SUMMARY

The discussion focuses on calculating the gravitational acceleration (g) using latitude and altitude above sea level. The relevant formula derived from Newton's law of universal gravitation is a(g) = G M / r^2, where G is the gravitational constant, M is the Earth's mass, and r is the distance from the Earth's center. The forum participants clarify that latitude, not longitude, affects the value of g due to the Earth's rotation. A reference link to the National Physical Laboratory's FAQ on gravity is provided for further information.

PREREQUISITES
  • Understanding of Newton's law of universal gravitation
  • Familiarity with Newton's second law of motion
  • Basic knowledge of gravitational constant (G)
  • Concept of distance from the Earth's center (r)
NEXT STEPS
  • Research the effects of latitude on gravitational acceleration
  • Explore the relationship between altitude and gravitational force
  • Learn about the Earth's mass and its implications in gravitational calculations
  • Investigate the impact of Earth's rotation on gravitational measurements
USEFUL FOR

Students in physics, geophysicists, and anyone interested in understanding gravitational calculations related to altitude and latitude.

Tawcan
Hi, new to here...

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!
 
Physics news on Phys.org
I assume you mean latitude, not longitude. g varies with latitude because of the Earth's rotation.

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
 
Oops you guys are right.

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

Similar threads

Replies
4
Views
2K
  • · Replies 3 ·
Replies
3
Views
9K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 16 ·
Replies
16
Views
15K
  • · Replies 12 ·
Replies
12
Views
3K
Replies
1
Views
2K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 13 ·
Replies
13
Views
3K