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### Two multiple choice questions I was stuck on ...

Posted: Sun Oct 29, 2017 8:31 pm

14. For large everyday objects does Heisenberg's uncertainty (indeterminacy) principle play any measurable role?

A. Yes, the uncertainties in position, speed, and momentum of a stationary object are noticeable or measurable.

B. Yes, the uncertainties in position, speed, and momentum of a moving object are noticeable or measurable.

C. No, the uncertainties in position, speed, and momentum of a stationary object are not noticeable or measurable.

D. No, the uncertainties in position, speed, and momentum of a moving object are not noticeable or measurable.

16. Which one of the following statements is correct in describing Heisenberg's uncertainty (indeterminacy) equation?

A. The less precisely the position is determined, the less precisely the momentum is known in this instant, and vice versa.

B. The more precisely the position is determined, the more precisely the momentum is known in this instant, and vice versa.

C. The more precisely the position is determined, the less precisely the momentum is known in this instant, and vice versa.

D. None of the above

### Re: Two multiple choice questions I was stuck on ...

Posted: Sun Oct 29, 2017 8:36 pm
The correct answer for 16 is C. Since Heisenberg's Indeterminacy Equation is (uncertainty of momentum) x (uncertainty of position) = h/4*pi, this means that uncertainty of momentum and uncertainty of position are inversely related. h/4*pi is a constant value, so if uncertainty of momentum is high, uncertainty of position must be low, and if uncertainty of position is high, uncertainty of momentum must be low.

### Re: Two multiple choice questions I was stuck on ...

Posted: Sun Oct 29, 2017 8:46 pm
For large, everyday objects the Heisenberg's Uncertainty Principle does not apply because the indeterminacy of momentum and position are so small that they're negligible. For example, when a baseball passes between two lasers, we are 100% certain of the path it took and the velocity/momentum it traveled with. The momentum of the baseball is so large that the photons from the laser don't have an affect on it. However, if we did the same experiment using an electron, the photons in the laser would interact with the electron, so it would change paths. Thus, the indeterminacy of position arises. Position and momentum are complementary properties; the more you know about one the less you know about the other. Since they have to be equal or greater to a small constant value ( h/(4pi) ), if the indeterminacy of position is very relatively very small, then the indeterminacy of the momentum has to be relatively larger to account for the equality.