The Pion (Mπ = 140 MeV/c²)is Thought to Be the Particle

Multiple Choice

The pion (mπ = 140 MeV/c²) is thought to be the particle exchanged in the nuclear force.What is the maximum range of this particle if its "time of existence" is as long as can be allowed by the uncertainty principle ΔE⋅Δt = h/2π? (h/2π = 1.05 × 10−³⁴ J⋅s,c = 3.00 × 10⁸ m/s,and 1 eV = 1.6 × 10−¹⁹ J)

A) 1.2 × 10−¹⁵ m
B) 1.4 × 10−¹⁵ m
C) 2.0 × 10−¹⁵ m
D) 7.5 × 10−¹⁵ m