## Heisenberg Indeterminacy Equation Calculations

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

Alex Nguyen 3I
Posts: 100
Joined: Fri Sep 25, 2015 3:00 am

### Heisenberg Indeterminacy Equation Calculations

The Indeterminacy Equation is $\Delta p\Delta x\geq \frac{h}{4\pi }$. Therefore, if you're given the uncertainty or indeterminacy of position, you would use the full range (+/-) since the position can take on any value within the spread right (i.e. 2x the indeterminacy of position)? Would the same idea be true for velocity or mass? Would you use the range if given it? If you're given the exact velocity or mass, would you just plug these values in? Wouldn't the indeterminacy technically be 0. Lastly if position is known exactly, how would that value be incorporated into the equation? Thanks in advance.

Andrew Ly 1A
Posts: 22
Joined: Fri Sep 25, 2015 3:00 am

### Re: Heisenberg Indeterminacy Equation Calculations

The same idea would be true if you were given the indeterminacy of velocity as a "+/-" value. For example, if the problem were to say that the velocity of a marble is known to within $\pm$1.0 mm$\cdot s^{-1}$, then the indeterminacy of velocity would be 2 x 1.0 mm$\cdot s^{-1}$ (remember to convert to SI unit of m) as shown in Example 1.7 of the sixth edition textbook. I have attached an image of the example referenced below.

Mass does not have an indeterminacy so you shouldn't need to worry about having an uncertainty in mass to plug into the Indeterminacy Equation.

Ex. 1.7 from Chemical Principles The Quest for Insight, Sixth Edition