When subatomic particles undergo reaction energy is conserved, but mass is not necessarily conserved. However, a particle's mass 'contributes' to its total energy, in accordance with Einstein'f famouns equation, `E= mc^(2)`
In this question, `E` denotes the equivalent energy when a particle of mass `m` is converted into energy. The particle can also have additional energy due to its motion and its interactions with other particles.
Consider a neutron at rest, and well separated from other particles. It decays into a proton, an electron, and an undetected third particle: `"Neutron"rarr"proton"+"electron"+"third particle"`
The table below summarizes some data from a single nuetron decay. Column `2` shows the rest mass of the particle times the speed of light squared.
`{:("Particle",Mx C^(2),,"Kinetic Energy",),(,(MeV),,(MeV),),("Neutron",940.97,,0,),("Proton",939.66,,0.02,),("Electron",0.51,,0.42,):}`
From the given table, which properties of the undetected third particle can we calculate ?

Options

A. Total energy but not kinetic energy
B. Kinetic energy, but not total energy
C. Both total energy, but not kinetic energy
D. Neither total energy nor kinetic energy

Answer

A

Explanation

Look to the solution of the above problem.