What is the gravitational force between two 60-kg people standing 2.0 m apart? Use G = 6.67 × 10⁻¹¹ N·m²/kg².
A6.0 × 10⁻⁸ N
B6.0 × 10⁻⁹ N
C1.2 × 10⁻⁷ N
D2.4 × 10⁻⁷ N
Explanation
📌 F = Gm₁m₂/d² = (6.67 × 10⁻¹¹)(60)(60)/(2.0)² = (6.67 × 10⁻¹¹)(3600)/4 = 6.0 × 10⁻⁸ N. Very small — that's why we don't feel our neighbor's gravity. Distractor B: order-of-magnitude slip; C: forgot to square distance (used 2 instead of 4); D: doubled.