Science questions/help thread

[Vatumok]

I have quite some free time at the moment and because I am bored and might want to become a teacher later I will answer people their questions about chemistry, physics or math(s). If you need help with your homework (and no, I will not do your homework for you), are in a debate with someone or just want to know something feel free to post something in this thread or send me a PM.

I'll list all the subjects that I have knowledge about:

Spoiler

Math(s)
Standard functions/algebra
Linear algebra
(Multivariable) Calculus
Trigonomy (High school level)
Geometry (High school level)
Complex numbers (High school level)

Physics
Classic (Rotational) Mechanics
Electricity/Magnetism/Electromagnetism

Chemistry
pH/acids/bases
Redox
Equilibria
Thermodynamics (Ideal gasses, Entropy, Enthalpy, Gibbs energy, etc..)
Organic chemistry (High school level)

Kind regards,
Vatumok

 

[YouWould]

Thermodynamics

please

 

[Vatumok]

Thermodynamics

please

You're gonna need to be a little more specific, I have to know what area and how many of it you have to learn. Questions would be ideal.

 

[Timdood3]

What exactly are Sine and Cosine? Like what do they represent? I have a vague idea of how they work in general, but have no idea what they represent.

Also could you explain entropy?

Woo.

 

[Vatumok]

What exactly are Sine and Cosine? Like what do they represent? I have a vague idea of how they work in general, but have no idea what they represent.

Also could you explain entropy?

Woo.

The sine and the cosine both come from the unit circle (radius = 1). You start at the most eastern part of the circle and then you move counter-clockwise around the perimeter of the unit circle. The distance you have travelled around the perimeter is generally given in radians (parts of the radius travelled, in this case one radian is of lenght 1) but angles can also be used. Now you are at a point on the unit circle, you can draw a line from the middle of the axis towards your point. That line can be broken down in x-part and a y-part. The x-part is called the cosine(x)/cos(x) and the y-part is called sine(x)/sin(x). I hope the picture below clears things up.

Entropy is very hard to understand (like most parts of thermodynamics) but basically it comes down to how many molacular/microscopic states a system can be in. It's often said that it's measure of dissorder, and that's a pretty good way to look at it. If something is order it's predictable while if it's dissordered it's hard to know where and how everything is. The second law says that the overall entropy must always increase, but things like a fridge (that have a low entropy) can be created by making a surrounding that generates a ton more entropy. That's all I can say about it, it's easier to understand the mathematics about it than the idea.

 

[Jayfeather]

it's easier to understand the mathematics about it than the idea.

I feel this T_T why are concepts so hard to grasp in comparison to the equations

 

[Vatumok]

I feel this T_T why are concepts so hard to grasp in comparison to the equations

Because things in thermodynamics and quantum theory are so small that you cannot really see how things work. Certain experiments can be done and with that models can be made. After those experiments you don't always have a full explanation for what happened and it's often easier to write mathetmatical models/relations than to really say what's going on.

Another reason could be that an equation is easy to read, if you have good understand of mathetmatic, and a text is a lot harder to read when things are complicated.

Some people say that mathematics is the language of nature, maybe.

 

[Mastersten]

How to make an atom bomb?

EDIT: Didn't read the list at the top :3 radiation wasn't in it :/

 

[Jayfeather]

How to make an atom bomb?

EDIT: Didn't read the list at the top :3 radiation wasn't in it :/

make atom tiny

 

[Vatumok]

How to make an atom bomb?

EDIT: Didn't read the list at the top :3 radiation wasn't in it :/

I do not know how to make an atomic bomb, or how it exactly works but the main principle (I believe) is that you let nuclear fission happen of uranium or plutonium which shoots out more than 1 neutron that lets more fission-reactions take place. You get a sort of chain reaction which creates a lot of heat.

 

[Jubjubers]

where can i buy a sub-critical mass of pu-239, everyones favourite weaponised plutonium isotope


it's for a friend

 

[YouWould]

where can i buy a sub-critical mass of pu-239, everyones favourite weaponised plutonium isotope

the dark gray market
not to be confused with the black market

 

[Timdood3]

the dark gray market
not to be confused with the black market

But have you heard of the dark white market?
Actually that sounds like it sells nothing but white drugs (e.g. cocaine)

 

[Jubjubers]

But have you heard of the dark white market?
Actually that sounds like it sells nothing but white drugs (e.g. cocaine)

it's like a sub-legal Waitrose.

 

[Damer_Flinn]

Vatumok I have an easy one for you.

Do you agree that this is totally awesome?
http://earth.nullschool.net/#curren...erlay=mean_sea_level_pressure/equirectangular

(click on "earth" in the lower corner for options)