Post- Module #18 and #23

$\Delta p \Delta x\geq \frac{h}{4\pi }$

Cam Bear 2F
Posts: 60
Joined: Thu Jul 27, 2017 3:01 am

Post- Module #18 and #23

Hi guys!
I'm confused on how to determine what delta x to use to solve both of these questions.

#18 states "The hydrogen atom has a radius of approximately 0.05nm. Assume that we know the position of an electron to an accuracy of 1% of the hydrogen radius, calculate the uncertainty in the speed of the electron using the Heisenberg uncertainty principle."

#23 states You are caught in a radar trap and hope to show that the speed measured by the radar gun is in error due to the Heisenberg uncertainty principle. If you assume that the uncertainty in your position was +/- 5 m when your speed was measured, and that the car has a mass of 2150 kg, what is your calculated uncertainty in the speed of your car?"

Thanks!

William Lan 2l
Posts: 73
Joined: Fri Sep 29, 2017 7:07 am

Re: Post- Module #18 and #23

#18: The delta X is uncertainty in position. It tells us that the uncertainty in position is 1% of .05 nm or .05 x 10^-9 m. So just do 1% of .05 x 10^-9 m and whatever answer you get is your delta X.

#23: The delta X in this problem is 10 m since we have to account for everything in between +5 and -5.