Suppose protons were emitted rather than electrons then it affects the experiment as the mean velocity of proton will be less then mean velocity electron .
The mass of proton is greater than the mass of electrons but charge of electron is equal to the charge of proton . So , due to difference in the mass of electron and proton there will be some effects. We can conserve the electric energy which is equal to the qe .
The kinetic energy = 1/2[tex]mv^{2}[/tex]
Now changing the electric potential energy into kinetic energy
v = √2qe/m
The mean velocity of proton will be less then mean velocity electron .
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