g Variation

Altitude, depth, latitude, shape.

Concept

g Variation is a foundational idea in this chapter. The defining relationship is:

$g_h \approx g(1 - 2h/R), \quad g_d \approx g(1-d/R)$

g_eff at equator < g at poles due to rotation and oblateness.

Worked Application

Apply the formula to a typical problem from your textbook. Identify the knowns, plug into the equation, and check that the units work out. Always sanity-check the magnitude before accepting an answer.

Common Confusions

• Confusing the variables in the formula — re-read the symbol definitions in the chapter.
• Forgetting unit conversions (cm vs m, g vs kg).
• Ignoring sign conventions where direction matters.

Key Takeaways

• Master the formula $g_h \approx g(1 - 2h/R), \quad g_d \approx g(1-d/R)$ and one canonical example.
• See the chapter index for full derivations, traps and exam-grade problems.