Question 1B 25

[Isis_DW_3G]

hey guys,
i was doing question 1b 25 in the textbook and it asks for the uncertainty in the velocity of a neutron with wavelength 350pm. i used our uncertainty equation (deltap*deltax > h/4pi) but the textbook uses (deltap * deltax > 1/2 h). my answer was close to the solution (attached below) but why are they using 1/2 instead of 4pi? will we have to use this?

When i did this problem with h/4pi I was pretty close to the book's answer (I got 1.63x10^6).

Thanks!

[Kayla Law 2D]

The textbook uses h-bar, which is equal to h/2pi. (1/2)h-bar and h/4pi are the exact same! You can use whichever you prefer :)

[Lung Sheng Liang 3J]

The textbook uses a different uncertainty equation that is basically the same thing. We'll be fine if we stick with the formula on the EQ sheet we use for our tests.