Recent content by triac

Hi! Today we discussed atomic physics in our class, and the following question came up: Consider an atom, and consider for example its three lowest energy states. Suppose these correspong to the energies E1,E2 and E3, respectively. Will it be possible for an electron in the lowest energy state...

Homework Statement Hi! I'm stuck on this one too. "A rock contains the radioactive isotope Rb-87. A piece of this rock contained 2,05*10^20 Rb-87 atoms and 8,25*10^20 decay products per kg. The half-life of Rb-87 is 47*10^9 years. How old is the rock?" Homework Equations...

Homework Statement A piece of Am-241 has a radioactivity of 10kBq. Determine how much Am-241 it contains. Homework Equations N(t)=N_0(\frac{1}{2})^{t/T_{1/2}} The Attempt at a Solution Let A be the activity Let N be the number of atoms We know that...

Ok, thanks for your help!

Hi! I am looking for a way to measure the voltage on a Kelvin Water Dropper that I've built. This is quite problematic since the charge is small and the voltage is high. The only way to do it, as it seems to me, is to measure by influence. Any suggestions?

Why is the "bending" of waves related to wavelength? Hi! As stated in the title, my question concerns the "bending" of waves. (I'm quite sure that "bending" is not the proper term, so if you know the correct one, please tell me.) Let's say that we investigate waves in a ripple tank. We create...

Ok, thanks a lot! I just wonder, why is it wrong to do the way I did, why doesn't it work?

Homework Statement Okay, so I'm going to find the smallest positive remainder of (21999+31998+51997) divided by seven. Homework Equations The Attempt at a Solution Well, I did like this: 23 is congruent to 1 (mod 7). Therefore, 21999= (23)1999/3 is congruent to 1 (mod 7). 33 is...

Thanks!

Ok, thanks a lot everybody! So, I downloaded Dev-C++ 4.9.9.2 and wrote some really basic program like this: #include <cstdlib> #include <iostream> using namespace std; int main() { cout<<"My first program"; return 0; } and then I chose compile and...

Hi! I would like to learn programming (I'm a beginner except for some programs on my calculator), and I need help. I had in mind to begin with C++, but I don't know of any good compiler for Windows. If anybody knows of one, and could tell me how I use the compiler (the language itself I can...

Thanks a lot for your help, it's very appreciated!

I guess I'll need some more help, if you have the time. I found out my temperature was a bit lower, 2635 K, and that I was supposed to integrate from 380 nm to 750 nm, so I would need another calculation. However, it would be good if I understand that with the constants a and b and the...

Thank you so much!

D'oh, it still peaks around origo. I just wonder, can you calculate integrals in this mathematica? If yes, would you mind calculating the ratio between the integral from 400 nm to 750 nm and the integral from zero to infinity, with the temperature 2800 K? I would just like to see the answer to...