Question: If a particle’s position uncertainty is zero, what can be said of its momentum uncertainty? If a particle’s position uncertainty is infinite, what can be said of its momentum uncertainty?

Short Answer

Expert verified

Answer:

For , x=0,phas to be , however, for x=, thenp could carry any value including zero.

Step by step solution

01

Uncertainty relation 

Mathematically, the uncertainty relation can be stated as ΔxΔph2.

02

Explanation 

Because this is the only method to preserve the uncertainty relation, which must be maintained for whatever measurements we take, if xis zero, we know that mustp be . Physically, these degrees of uncertainty correspond to a particle whose real momentum cannot be established but whose position is completely determined (probability density at a single point).

Regarding the infinite uncertainty in locationx= , we are aware that any value of , up to and including zero, will result in the satisfaction of the uncertainty relation.

This condition is analogous to an infinitely wide wave that is capable of carrying any value of momentum.

Thus,x=0pfor , has to be , however, forx=, thenpcould carry any value including zero

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

To how small a region must an electron be confined for borderline relativistic speeds say0.05to become reasonably likely? On the basis of this, would you expect relativistic effects to be prominent for hydrogen's electron, which has an orbit radius near10-10m? For a lead atom "inner-shell" electron of orbit radius10-12m?

Question: Incandescent lightbulbs heat up a filament “white hot,” producing light of all wavelengths that has little to do with the filament’s composition. Gas vapor bulbs, such as sodium and mercury streetlights, produce colors that do depend on the gas in the bulb. Viewed with a diffraction grating (even a simple CD!), whereas the incandescent spectrum is continuous, that of a gas vapor (or fluorescent) bulb has characteristic lines. How is this indirect evidence of the wave nature of orbiting electrons?

10A beam of electrons strikes a barrier with two narrow but equal-width slits. A screen is located beyond the barrier. And electrons are detected as they strike the screen. The "center" of the screen is the point equidistant from the slits. When either slit alone is open,electrons arrive per second in a very small region at the center of the screen. When both slits are open, how many electrons will arrive per second in the same region at the center of the screen?

One of the cornerstones of quantum mechanics is that bound particles cannot be stationary-even at zero absolute temperature! A "bound" particle is one that is confined in some finite region of space. as is an atom in a solid. There is a nonzero lower limit on the kinetic energy of such a particle. Suppose minimum kinetic energy of width L. Obtain an approximate formula for its minimum kinetic energy.

A particle is connected to a spring and undergoes one-dimensional motion.

(a) Write an expression for the total (kinetic plus potential) energy of the particle in terms of its position x. its mass m, its momentum p, and the force constantof the spring.

(b) Now treat the particle as a wave. Assume that the product of the uncertainties in position and momentum is governed by an uncertainty relationp.r12h. Also assume that because xis on average. the uncertaintyis roughly equal to a typical value of|x|. Similarly, assume thatp|p|. Eliminate pin favor of xin the energy expression.

(c) Find the minimum possible energy for the wave.

See all solutions

Recommended explanations on Physics Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free