# Quantum Physics

posted by .

A proton is confined in an atomic nucleus of size 2 fm. Determine the fundamental limit on
the uncertainty of any prediction for the measurement of the momentum of the proton in the
nucleus.

• Quantum Physics -

The uncertainty in proton location is
deltax = +/- 1 fm = 10^-15 m

The uncertainty in x-momentum is
deltaPx = (h/4pi)/deltax = 5*10^-20 kg m/s

where h is Planck's constant.

Your book may eliminate the 1/(4 pi) factor. It depends upon how the uncertainty is defined. The h/4 pi value is the product of standard deviations.

Remember that there are uncertainties in three directions of momentum. The total momentum uncertainty is a factor of sqrt3 higher.

I would not be surprised if your book's answer is up to a factor of ten different.

No wonder they call it the uncertainty principle. :-)

• Quantum Physics -

I don't understand why you've used 4 pi in your answer, i assume your rearranged the uncertainty principle equation for delta Px, but isnt the reduced plancks constant h/ 2pi instead of 4pi ?

## Similar Questions

1. ### Science

which action would result in the more (financially) valuable product: taking one proton from each nucleus in a sample of gold or adding one proton to each gold nucleus?
2. ### PHYSICS

A proton is confined to a nucleus whose diameter is 5.5*10^-15m. If this distance is considered to be the uncertainty in the position of the proton, what is the minimum uncertainty in its momentum?
3. ### chemistry

1. name the three fundamental particles present in an atom?
4. ### physics

A proton that has a mass m and is moving at 250 m/s in the + direction undergoes a head-on elastic collision with a stationary oxygen nucleus of mass 16m. Find the velocities of the proton and the oxygen nucleus after the collision …
5. ### physics

A proton that has a mass m and is moving at 250 m/s in the + direction undergoes a head-on elastic collision with a stationary oxygen nucleus of mass 16m. Find the velocities of the proton and the carbon nucleus after the collision
6. ### math

Need help on this problem. The mass of a proton is about 1.7 x 10^-24g. The mass of a neutron is about the same as a proton. The nucleus of an atom of carbon has 6 protons and 6 neutrons. The mass of the nucleus is about 2 x 10^-26 …
7. ### Physics

A proton is fired from far away toward the nucleus of a mercury atom. Mercury is element number 80, and the diameter of the nucleus is 14.0 fm. The proton is fired at a speed of 1.80×107 m/s. When it passes the nucleus, how close …
8. ### Physics

I don't know how to go about this question. We only have an initial velocity and no final velocity, distance or time. A proton is fired from far away toward the nucleus of a mercury atom. Mercury is element number 80, and the diameter …
9. ### physics

A proton is projected at a stationary 6238 Ni aluminum target. The proton momentarily comes to a halt at a distance from the center of an aluminum nucleus, equal to twice the nuclear radius. Assume that the nucleus retains its spherical …
10. ### physics

A proton is confined to a nucleus of radius 5 FM.what's the minimum uncertainty in momentum?

More Similar Questions