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Imagine playing baseball in a universe (not ours!) where the Planck constant is 0.60 J.s, and thus quantum physics affects macroscopic objects. What would be the uncertainty in the position of a 0.50 kg baseball that is moving at 20 m/s along an axis if the uncertainty in the speed is 1.0 m/s?

Short Answer

Expert verified

The uncertainty in the position of the baseball that is moving along an axis is 0.191 m.

Step by step solution

01

Identification of the given data

The given data can be listed below as,

  • The value of the Plank’s constant is,h=0.60J·s .
  • The mass of the baseball is,m=0.50kg .
  • The speed of the baseball is, v=20m/s.
  • The uncertainty in the speed is, Δv=1.0m/s.
02

Significance of the uncertainty principle

In this question, the value of the uncertainty in the baseball position can be determined with the help of the Heisenberg uncertainty principle. The relation between the uncertainty in position and speed is an inverse one.

03

Determination of the uncertainty in the position of the baseball

The expression to calculate the uncertainty in the position of the baseball is expressed as,

ΔxΔp=h2πΔx=h2πΔp=h2πmΔv

Here, Δxi s the uncertainty in the position of the baseball, Δpis the uncertainty in the momentum of the baseball.

Substitute all the known values in the above equation.

Δx=0.60J·s2π0.50kg1.0m/s≈0.191J·s2/kg·m≈0.191J·s2/kg·m1m1J·s2/kg·m≈0.191m

Thus, the uncertainty in the position of the baseball is 0.191 m.

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