i know this is a silly question, but i couldn't manage to wrap my head around it. I am kinda new to electronics. My home's outlets provide 220V. Upon doing some (a lot) research, the current that this voltage can supply is enough to kill me. However, when i try to do the maths myself, i can't se...

I don't have much of a physics background, so my assumptions might be somewhat incorrect. But I've recently seen how sanding tools can be used on materials that are powerful, such as stainless steel. From a Google search, it seems standard sanding tools are made out of materials like aluminum oxi...

I have a question regarding capacitors and their charge neutrality. When capacitors are used in circuits, the assumption is often made that the plates of the capacitors have equal and opposite charges. I was wondering why this is the case. I have done some research. One source, The Feynman Lectu...

Do tangential velocity and tangential acceleration change with radius (change of radius on the same object)? For example consider a spinning disk. Does the equation $$a_t = \alpha R$$ (where $a_t$ is the tangential acceleration, $\alpha$ is the angular acceleration and $R$ is the radius of the ...

I have written in some old notes that the FLRW (also known as FRW) metric can be written as: $$ds^2=dt^2 + a^2 (t) [dr^2 +r^2(d\theta^2 + sin^2\theta d\varphi ^2)] \tag{1}$$ I believe this is its representation in $4\text{D}$. But I have seen in other pages, among them, the Wikipedia page and ...