7. A neutron at rest decays (breaks apart) into a proton and an electron. Energy is released in the decay, in the form of kinetic energy of the proton and electron. The mass of a proton is 1836 times the mass of an electron. What fraction of the total energy released goes into the kinetic energy of the proton?

Respuesta :

Answer:

The fraction of the total energy goes into kinetic energy of proton is [tex]5.44 \times 10^{-4}[/tex]

Explanation:

Given:

Mass of proton [tex]m_{p} = 1836 m_{e}[/tex]

Mass of electron [tex]m_{e} = 9.1 \times 10^{-31}[/tex] kg

Here neutron at rest decays into proton and electron

   [tex]n_{1} ^{0}[/tex]  ⇄ [tex]P_{1} ^{1} + e_{0} ^{-1} + Q[/tex]

Where [tex]Q =[/tex] energy released

The [tex]Q[/tex] value of this reaction is given by

    [tex]Q = (\frac{m_{p} +m _{e} }{m_{e} } ) K[/tex]

Where [tex]K =[/tex] kinetic energy of reaction

Here we need to find fraction of the total energy released goes into the kinetic energy of the proton

   [tex]\frac{K}{Q} = \frac{m_{e} }{m_{p} + m_{e} }[/tex]

   [tex]\frac{K}{Q} = (\frac{m_{e} }{1836m_{e} + m_{e} } )[/tex]

   [tex]\frac{K}{Q} = \frac{1}{1837}[/tex]

   [tex]\frac{K}{Q} = 5.44 \times 10^{-4}[/tex]

Therefore, the fraction of the total energy goes into kinetic energy of proton is [tex]5.44 \times 10^{-4}[/tex]