It might seem strange that in beta decay the positive proton, which is repelled by the positive nucleus, remains in the nucleus while the negative electron, which is attracted to the nucleus, is ejected. To understand beta decay, let's analyze the decay of a free neutron that is at rest in the laboratory. We'll ignore the antineutrino and consider the decay n → p⁺ + e⁻. The analysis requires the use of relativistic energy and momentum, from Chapter 36.b. Write the equation that expresses the conservation of relativistic energy for this decay. Your equation will be in terms of the three masses mₙ, mₚ and mₑ and the relativistic factors yₚ and yₑ.