Quantum Mechanics: Probability of the result h-bar/2 if Sy is measured

In summary, the probability of measuring h-bar/2 is the same as the probability of finding the particle in the state ψ+. This is because Syψ+ = (h-bar/2)Syψ+, and the solution provided in the problem statement is incorrect as it includes the matrix Sy which should be left out in the calculation of the probability. It should be noted that the probability must be a dimensionless number, but the given solution has dimensions of h2.
  • #1
bbnl1990
3
0

Homework Statement



http://dl.dropbox.com/u/24280471/Question.PNG
http://dl.dropbox.com/u/24280471/Answer.PNG

Homework Equations



Isn't the probability of measuring h-bar/2 the same as the probability of finding the particle in the state ψ+? Since Syψ+ = (h-bar/2)Syψ+.

The Attempt at a Solution



(Sorry, don't know how to use LaTex.)
http://dl.dropbox.com/u/24280471/Attempt.PNG
 
Last edited by a moderator:
Physics news on Phys.org
  • #2


bbnl1990 said:
Isn't the probability of measuring h-bar/2 the same as the probability of finding the particle in the state ψ+?
Yes, your solution is correct. The answer in the problem statement is incorrect. They should have left out the matrix Sy in the calculation of the probability. Note that the probability must be a dimensionless number, but they are getting something that has the dimensions h2.
 
  • #3


Yes, your solution is correct. The answer in the problem statement is incorrect. They should have left out the matrix Sy in the calculation of the probability. Note that the probability must be a dimensionless number, but they are getting something that has the dimensions h2.

Thank you for your reply!
 

Related to Quantum Mechanics: Probability of the result h-bar/2 if Sy is measured

What is the meaning of h-bar/2 in quantum mechanics?

In quantum mechanics, h-bar/2 refers to the reduced Planck's constant, which is a fundamental constant used to describe the behavior of particles at the quantum level.

What is the significance of measuring Sy in quantum mechanics?

In quantum mechanics, Sy refers to the spin of a particle along the y-axis. Measuring Sy allows us to determine the spin state of a particle and make predictions about its behavior.

What does the probability of the result h-bar/2 if Sy is measured represent?

The probability of the result h-bar/2 if Sy is measured represents the likelihood of obtaining a spin measurement of h-bar/2 along the y-axis. This probability is calculated using the principles of quantum mechanics and can vary depending on the specific system being studied.

How is the probability of h-bar/2 if Sy is measured calculated?

The probability of h-bar/2 if Sy is measured is calculated using the Schrödinger equation, which describes the evolution of quantum systems. This equation takes into account the initial state of the system, the measurement being made, and the properties of the system itself to determine the probability of obtaining a specific measurement result.

What other factors can affect the probability of h-bar/2 if Sy is measured?

The probability of h-bar/2 if Sy is measured can also be affected by external disturbances or interactions with other particles. Additionally, the uncertainty principle in quantum mechanics states that it is impossible to know the exact values of certain properties, such as position and momentum, simultaneously. This uncertainty can also impact the probability of obtaining a specific measurement result.

Similar threads

  • Advanced Physics Homework Help
Replies
9
Views
353
  • Advanced Physics Homework Help
Replies
1
Views
816
  • Advanced Physics Homework Help
Replies
7
Views
2K
  • Advanced Physics Homework Help
Replies
14
Views
1K
  • Advanced Physics Homework Help
Replies
3
Views
2K
Replies
11
Views
1K
  • Advanced Physics Homework Help
Replies
5
Views
2K
Replies
5
Views
1K
  • Advanced Physics Homework Help
Replies
6
Views
2K
  • Advanced Physics Homework Help
Replies
1
Views
1K
Back
Top