Because a nucleon is confined to a nucleus, we can take its uncertainty in position to be the approximately the nuclear radius R. Using the uncertainty principle, we have to estimate the kinetic energy of a nucleon in a nucleus with, say . We may take the uncertainty in momentum to be the actual momentum p.

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For estimating the radius of a nucleus of mass number, we will use the empirical relation

Therefore, the radius R of a nucleus of mass number 100 will be

The Heisenberg uncertainty relation is

We take uncertainty in position to be approximately the nuclear radius R, i.e.

and uncertainty in momentum to be the momentum of the nucleon, i.e.

.

Using the uncertainty relation, we find

For the mass of a nucleon we take the mass of proton

Our estimate of the kinetic energy of a nucleon in a nucleus of mass number 100 is