1. The problem statement, all variables and given/known data

As the result of the weak interaction a neutron recomposes to a proton and an electron. Could the electron exist inside the neutron? Assume that the radius of the neutron is $10^{-15}m$.

2. Relevant equations

$$\Delta p =\frac{h}{2\pi \Delta x}$$

$$E=\frac{p^2}{2m}$$

3. The attempt at a solution

The book shows an equation as the solution of the exercise:

$$E=\frac{p^2}{2m (\Delta x)^2}\approx 1,5\cdot 10^{-19} J$$

I just can not understand how the $(\Delta x)^2$ got into the denominator of the fraction.

http://ift.tt/1g1Yqqq