The attractive force between protons and neutrons in the nucleus is brought about by the exchange of a virtual pi-meson (mπ = 140 MeV/c²).Estimate the longest time a π can exist in accordance with the uncertainty principle ΔE⋅Δt = h/2π.(h/2π = 1.05 × 10−³⁴ J⋅s,1 eV = 1.6 × 10−¹⁹ C) A)3.3 × 10−¹⁸ s B)2.4 × 10−²¹ s C)4.7 × 10−²⁴ s D)6.9 × 10−²⁷ s

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Quizplus · Accepted Answer

The uncertainty principle gives Δt = h/(2πΔE). Converting 140 MeV to joules, ΔE = 140 × 1.6 × 10^-13 J. Substituting the values, Δt ≈ 4.7 × 10^-24 s.

The Attractive Force Between Protons and Neutrons in the Nucleus