### Heisenberg Problem

Posted:

**Tue Nov 05, 2019 9:53 pm**An e- moving near an atomic nucleus has speed 6x10^61% m/s.

How do you find the uncertainty of its position?

How do you find the uncertainty of its position?

Created by Dr. Laurence Lavelle

https://lavelle.chem.ucla.edu/forum/

https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=19&t=50568

Page **1** of **1**

Posted: **Tue Nov 05, 2019 9:53 pm**

An e- moving near an atomic nucleus has speed 6x10^61% m/s.

How do you find the uncertainty of its position?

How do you find the uncertainty of its position?

Posted: **Tue Nov 05, 2019 10:19 pm**

So Heisenberg's uncertainty equation is basically (uncertainty in position)*(uncertainty in momentum)=h/4pi. Since we have uncertainty in speed, +- 1 m/s, we can find uncertainty in momentum by multiplying it by the mass of an electron, 9.11*10^-31. Then we can divide that value from both sides to get uncertainty in position = h/(4pi*uncertainty in momentum). Solve for this and you should get the value for uncertainty in position.

Posted: **Tue Nov 05, 2019 10:23 pm**

To find the uncertainty of position, you would use the equation ΔpΔx is greater than or equal to h/4pi

1) Rearrange the equation to isolate Δx (uncertainty of position) to get Δx is greater than or equal to h/(4pi Δp)

2) Find Δp. We're given the the speed from which we can calculate Δv and subsequently Δp. Use the equation Δp=mΔv to solve for Δp.

2.5) Δv can be calculated by taking the value after +/- symbol and multiplying it by 2.

3) Plug in your calculated value for Δp to the equation and get Δx

If there's any mistakes, please correct me :)

1) Rearrange the equation to isolate Δx (uncertainty of position) to get Δx is greater than or equal to h/(4pi Δp)

2) Find Δp. We're given the the speed from which we can calculate Δv and subsequently Δp. Use the equation Δp=mΔv to solve for Δp.

2.5) Δv can be calculated by taking the value after +/- symbol and multiplying it by 2.

3) Plug in your calculated value for Δp to the equation and get Δx

If there's any mistakes, please correct me :)

Posted: **Tue Nov 05, 2019 10:31 pm**

the mass of the electron will be given on the midterm, fyi