## Module Q 23

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

Jane Burgan 1C
Posts: 73
Joined: Fri Sep 28, 2018 12:15 am

### Module Q 23

23. 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?

I got Delta v >= 5 * 10 m/s but that's wrong. How do you do this problem?

Max Hayama 4K
Posts: 63
Joined: Fri Sep 28, 2018 12:16 am

### Re: Module Q 23

To start off, we need to find dp because momentum will allow us to find velocity. Therefore, you divide planck's constant by (4pi * dx), dx being the uncertainty of distance which is 10. Doing this will give you 5e-36 kg*m*s-1, our uncertainty in momentum, and using p=mv, you divide momentum by the mass of the car and you will get 2e-39 m/s.