The acceleration due to gravity g at height h above Earth's surface (radius R) is approximately

1. g_h = g × R² / (R + h)². 2. For h ≪ R, expand: (1 + h/R)⁻² ≈ 1 − 2h/R. 3. So g_h ≈ g × (1 − 2h/R) to first order. 4. This is the fractional decrease in g as we rise above Earth's surface. _Source: syllabus Physics, Ch 7 "Gravitation", §7.4_