Recent content by reckon

because the wavelength of tv antenna is in the same order of magnitude with your hand. A UHF frequency have wavelength between 10 cm to 1m while VHF frequency have wavelength between 1 to 10 m. [data taken from Wikipedia] Hope it explains

An old thread, but hope this posting will give something to anyone confused on this topic and ended up here (just like me). I tried to derive this on my own but didn't get the factor 1/4. I got the proportionality value only c, which I thought physically sensible because the energy inside the...

radiation is the way charges interact with each other from far, far away. If you calculate interaction energy between these charges, you should get the same result as you calculated using radiation method. *haven't prove what I said. That's my understanding of what I've read from books.

Hahaha.. thanks tiny-tim for ∑ and you even provided with "for copying-pasting" in your signature. But I'm still a bit unsure because for eθ eφ, we only have angle which doesn't have dimension, isn't it? Can we make them as component of a vector? A=rer + θeθ + φeφ where r have length...

as Vo is y direction is zero Vy(t)=-g exp(-z(t+6))-16 Vy=dy/dt, it makes dy= (-g exp(-z(t+6))-16 )dt and you get what you want

A vector A, can be expressed in sigma notation as \sum Ai where i runs from 1 to 3, i.e. A1 for x coordinate, A2 for y coordinate and A3 for z coordinate. I wonder how to express vector A in polar form using sigma notation. Could anyone share their knowledge to me?

yes, to differentiate the x^(x+1) f(x)=x+x^(x+1)-1 let y=x^(x+1) apply the log trick to y to get y' and you will get f'(x) as f'(x)=1+y'

y=x(1+x^x)-1=f(x)=0 => ln(y)=ln(0) ? why not differentiate f(x)=x(1+x^x)-1 and use the log method to differentiate just x^x part?

Is there anyone who knows on how's the information being transferred from eyes to brain? I'm not asking about how a single optical nerve works here, but how does these nerves arranged so that they can convey a 'live video' from eyes to brain. Is it a matrix of optic nerves with a single nerve...