Assume that protons and neutrons have equal masses. Mass of a nucleon is 1.6 × 10⁻²⁷ kg and radius of nucleus is 1.5 × 10⁻¹⁵ A¹ᐟ³ m. The approximate ratio of the nuclear density and water density is n × 10¹³. The value of n i s _______ .

Question

G1 Physics · Accepted Answer

Nuclear density ρ = (1.6×10⁻²⁷ A)/[(4/3)π(1.5×10⁻¹⁵)³A] ≈ 0.113×10¹⁸ kg m⁻³. Water density is 10³ kg m⁻³. Thus ρ/ρ_w ≈ 11.31×10¹³, so n ≈ 11.