# The Heisenberg Uncertainty Principle

1. Apr 7, 2010

### Physics321

1. The problem statement, all variables and given/known data
A proton in a tin nucleus is known to lie within a sphere whose diameter is about 2.2 multiplied by 10E-14 m. What are the uncertainties in the momentum and kinetic energy of the proton?

2. Relevant equations
delta(x)*delta(p) >= hbar
delta(E)*delta(t) >= hbar

3. The attempt at a solution

I understand the first part finding the uncertainty of the momentum, which is simply. . .

1.05E-34 J(s) / (2.2E-14 m) = 4.77E-21 kg(m/s)

I don't however, in any way understand finding the uncertainty in the kinetic energy. . . Howe are we suppose to know this if we aren't told the time (or does that matter). I know the answer should be something times E-14, but I would like to know how to modify and manipulate this equation (delta(E)*delta(t) >= hbar.

Any help would be appreciated.

2. Apr 8, 2010

### Redbelly98

Staff Emeritus
I think you just need to find the kinetic energy corresponding to the momentum you have calculated.