## Using the equation

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

Posts: 72
Joined: Wed Sep 18, 2019 12:18 am

### Using the equation

Can somebody please explain to me how we would use this equation? The example in the textbook makes sense but when I go to actually apply it it does not make sense at all. Like they'll give us the weight in grams but I'm not sure how that's relevant. Thank you!

JamieVu_2C
Posts: 85
Joined: Thu Jul 25, 2019 12:16 am

### Re: Using the equation

Can somebody please explain to me how we would use this equation? The example in the textbook makes sense but when I go to actually apply it it does not make sense at all. Like they'll give us the weight in grams but I'm not sure how that's relevant. Thank you!

The equation is (delta p)(delta x) >/= h/4pi.
delta p = uncertainty in momentum, which also equals (mass in kg)(uncertainty in velocity)
delta x = uncertainty in position
h = Planck's constant

The weight in grams is used for delta p since delta p = (mass in kg)(uncertainty in velocity. You would just convert the grams to kg for the mass and you would plug in the uncertainty in velocity to get delta p. Once you find delta p, then you can find the other unknown, which is delta x, the uncertainty in position.

Amy Kumar 1I
Posts: 92
Joined: Thu Jul 11, 2019 12:15 am

### Re: Using the equation

You use the equation to find uncertainty in position or velocity, depending on what is given. If, for example, the velocity is given as 10 +/- 2 m/s, delta(velocity) would be 4 m/s and the question may ask you to find the difference in position (delta(position)) while the mass remains constant.