Minimum uncertainty of the momentum of a small particle

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SUMMARY

The minimum uncertainty of the momentum of a small particle with mass m=1g confined within a region of width a=1cm can be calculated using the Heisenberg uncertainty principle, expressed as Δp * Δx ≥ ℏ/2. In this case, substituting Δx with 10^(-2) m leads to Δp = 10^2 * ℏ/2. The mass provided in the problem is irrelevant for this calculation, as the focus is on the uncertainties in position and momentum rather than the mass itself.

PREREQUISITES
  • Understanding of the Heisenberg uncertainty principle
  • Familiarity with quantum mechanics concepts
  • Basic knowledge of variances and standard deviations
  • Ability to manipulate equations involving Planck's constant (ℏ)
NEXT STEPS
  • Study the implications of the Heisenberg uncertainty principle in quantum mechanics
  • Learn about the concept of a particle in a box and its quantum states
  • Explore the relationship between uncertainty in position and momentum
  • Investigate the role of mass in quantum mechanics and its effects on particle behavior
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Students and professionals in physics, particularly those focusing on quantum mechanics, as well as educators teaching the principles of uncertainty in particle physics.

AndrejN96
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Homework Statement


Find the minimum uncertainty of the momentum of a small particle with mass m=1g, which is confined within a region of width a=1cm.

Homework Equations


Delta(p)*Delta(x)>=hbar/2

The Attempt at a Solution



Delta(p)*Delta(x)=hbar/2
Delta(p)*10^(-2)=hbar/2
Delta(p)=10^2*hbar/2

This looks pretty straightforward to me, but the given mass in this problem is what confuses me.
 
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I think you have it right & putting in the mass is a red herring. Maybe they meant to ask for the minimum uncertainty in the velocity.
 
You might want to scan this:

http://en.wikipedia.org/wiki/Particle_in_a_box

Pull quote:

"The uncertainties in position and momentum (
b56546a86ab832a9b2a5b15f96519319.png
and
7aa41487a1a40b0077afa0c3331ba111.png
) are defined as being equal to the square root of their respective variances, so that:

a83e98aee94cda7f0410e16698b54ebf.png

This product increases with increasing n, having a minimum value for n=1. The value of this product for n=1 is about equal to 0.568
9dfd055ef1683b053f1b5bf9ed6dbbb4.png
..."
 

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