Impossible heisburg uncertainty question that makes no sense

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SUMMARY

The discussion centers on calculating the minimum uncertainty in speed for a quantum-mechanical duck named Fuzzy, using the equation xp = h/4π. The user initially calculated an uncertainty of 8.88 m/s, which was identified as incorrect by other participants. The correct approach involves using the uncertainty principle, leading to a revised uncertainty in speed of approximately 0.87 m/s, factoring in the mass of 1.80 kg and the width of the pond as 1.00 m.

PREREQUISITES
  • Understanding of quantum mechanics principles, specifically the Heisenberg uncertainty principle.
  • Familiarity with the equation xp = h/4π and its application in uncertainty calculations.
  • Basic knowledge of mass and velocity concepts in physics.
  • Ability to perform unit conversions and dimensional analysis in physics problems.
NEXT STEPS
  • Study the Heisenberg uncertainty principle in detail to grasp its implications in quantum mechanics.
  • Learn how to apply the equation xp = h/4π in various scenarios involving different particles.
  • Explore the concept of velocity versus speed and their significance in uncertainty calculations.
  • Review examples of quantum mechanics problems that involve uncertainty calculations for better understanding.
USEFUL FOR

Students of quantum mechanics, physics enthusiasts, and anyone involved in solving problems related to the Heisenberg uncertainty principle will benefit from this discussion.

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Homework Statement



Suppose Fuzzy, a quantum-mechanical duck, lives in a world in which h = 2πJ · s. Fuzzy has a mass of 1.80 kg and is initially known to be within a pond 1.00 m wide. (a) What is the minimum uncertainty in the duck's speed?
1(b) Assuming this uncertainty in speed to prevail for 5.40 s, determine the uncertainty in Fuzzy's position after this time.

Homework Equations


xp=h/4(3.14)


The Attempt at a Solution


tried it a million different ways
 
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Well can you tell us what you tried, and tell us the right answer that you are failing to get?
 
im doing online homework
 
(a) I plugged all the numbers into the equation using 2pie for h and I get 8.88 and its off by orders of magnitude (b) I have no idea
 
How did you get 8.88?
if delta x * m * delta v = h/4 = 2pi / 4 = pi / 2
then
delta v = Pi / (2 * 1 m * 1.8 kg) = Pi Js / 3.6kgm
pi/3.6 is NOT 8.88 ... it's going to be a little less than 1

and that's not even considering the fact that the uncertainty in speed should be half of the uncertainty of velocity (though I've even seen some textbooks that don't even consider the fact that velocity can be in both directions, and take the uncertainty in velocity to be the uncertainty in speed...however, the book that i learned quantum mechanics from had the uncertainty in speed as half the uncertainty in velocity for all the questions ...i don't know how your online service works, but if 8.88 is off by EXACTLY an order of magnitude, then the real answer would be 0.87 and not half of that)
 
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