If light of certain wavelength falls on two particles say electron and a neutron(isolated) then since they are absorbing the same amount of energy their kinetic energy must be same.(adsbygoogle = window.adsbygoogle || []).push({});

But using the formula:

$$ \lambda = \frac{h}{\sqrt{2mE}} $$

we get

$$ E = \frac{h^2}{2m \lambda^2}$$

which states us that for same wavelength kinetic energy varies inversly with mass thus neutron would have less kinetic energy than electron mathematically but logical approach states that for same wavelength of light falling on both, they absorb same amount of energy thus kinetic energy must be same.

Why mathematical and logical aspects are not giving the same result?

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# Kinetic energy of two particles

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