/sci/ - Science & Math

>>11640071
Lens is just a body a ray passes through. Two assumptions typically made in classical optics are
>small angle approximation
>all surfaces are either flat or sections of a circle/sphere
In reality, only parabolas focus to a point. But, when the radius of curvature of a circular section is much greater than its arc length (as with any lens in geometric optics), you can assume it focuses like a parabola.
>>11639520
>high school
hyper physics
>>11638002
kek
>>11637819
It's both. The more of an insulator a substance is, the more likely it is to donate ions as the charge carrier instead of electrons. A metallic surface isn't going to have ions to donate in any case, because of how metal atoms bond to another. Ceramics possibly do have those ions, though, and if those ions have opposite polarity of the ceramic surface it abrades against, you may get transfer.
>Or more importantly, how could I calculate by myself the energy required to remove an electron from an atom inside a molecule, and the energy required to break a molecule into its ions?
You build a work function.
>Pan, S., Zhang, Z. Fundamental theories and basic principles of triboelectric effect: A review. Friction 7, 2–17 (2019). [woops cant put the link here, google is your friend]
>sections 2.2 and 2.3
Basically its just the difference between the electrostatic potential and the Fermi level.

>>11434854
Dam has thickness [math] t=1\ \text{ft} [/math]. Water has weight [math] \gamma=62.4\ \text{lbs/ft}^3 [/math]. Height is [math] h=18\ \text{ft} [/math]. It is known that pressure is proportional to depth, specifically [math]
p=\gamma y [/math] The horizontal component of the hydrostatic force on the dam is then [eqn] P=\int p\ \text{d}A=\int_0^t\int_0^h\gamma y\ \text{d}y\text{d}z=\frac{1}{2}\gamma h^2t=\frac{1}{2}(62.4)(18)^2(1)=10\ 109\ \text{lbs} [/eqn]

Because pressure increases linearly, the center of pressure (i.e., the centroid of the pressure distribution) is [math] 2h/3=12\ \text{ft} [/math] deep.

>>11434167
>

>>11434264
Agreed. Trans rights are human rights~

>>11071763
https://en.wikipedia.org/wiki/Jacobi_ellipsoid

>>10567477
I didn't disagree with anything

>>10445196
You did the right thing, actually.

>>10403598
>dude how do averages work
If one man fucks 13 women, and two other men fuck 1 woman each, "the average man" has still fucked 5 women. Dumb incel.

>>10217812
Great idea, OP, but Copernicus already beat you to that idea by a few hundred years. In 1559 he convinced Polish king Sigismund II to finally place the earth into space.

>i just wanna make a minor scale fusion device in my backyard pls help lol