# Quantum mechanics minimum uncertainty

URGENT!! quantum mechanics question

## Homework Statement

In the lungs there are tiny sacs of air, which are called alveoli. The average diameter of one of these sacs is 0.25nm. Consider an oxygen molecule(mass=5.3x10^-26kg) trapped with a sac. What is the minimum uncertainty in the velocity of this oxygen molecule?

## Homework Equations

I'm not sure what equation I should use...then I'll post what the possible answer is

## Answers and Replies

Related Introductory Physics Homework Help News on Phys.org
I'm reading a similar section in my physics textbook, and I came across an equation ... in the section for Heisenberg's uncertainty principle.

$$\Delta x \Delta p \geq \frac{h}{2\pi}$$, where h is Planck's constant.

Hope that helps?

Hey LHC, thanks for the quick reply :)

I know that nm=r and kg=m but how would I sub it into the equation you mentioned?

x--> uncertainty in particle's position...
p--> uncertainty in particle's momentum...

Redbelly98
Staff Emeritus
Science Advisor
Homework Helper
So the equation will tell you the uncertainty in the momentum. Find that.

p.s. and watch the units ... use meters, kg, & sec for everything.