Verify that the Chapter 2 formula $\mathit{\Delta }\mathit{K}\mathit{E}\mathbf{=}\mathbf{-}\mathit{m}{\mathit{c}}^{\mathbf{2}}$ applies in Example 3.4.

The kinetic energy is described as the energy obtained by a particular body in motion. Moreover, it is also described as the work required to move a body from the rest position.

The one part of the example 3.4 is about finding out the energy of a photon. Hence, for finding out the energy of a photon, the law of the energy conservation of work done is needed. As there are helium and deuterium, then according to the law of energy conservation, the addition of the Planck’s equation and the product of the mass of helium and velocity of light should be equal to the two times of the product of the mass of deuterium and velocity of light which gives the energy of the photon. However, the product of the mass of the deuterium or proton and the velocity of light is the kinetic energy. Hence, proved.

Thus, the chapter 2 formula$\mathit{\Delta }\mathit{K}\mathit{E}\mathbf{=}\mathbf{-}\mathit{m}{\mathit{c}}^{\mathbf{2}}$ applies in example 3.4.