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seen Aug 8 '12 at 15:10

Aug
8
revised Voltage and resistance in series connection
Changed U to V
Aug
8
revised Voltage and resistance in series connection
Changed U to V
Aug
8
answered Voltage and resistance in series connection
Aug
7
comment Voltage and resistance in series connection
I know the definition as energy per charge.
Aug
7
asked Voltage and resistance in series connection
Jul
29
awarded  Supporter
Jul
29
accepted Radioactive decay, why such unintuitive formula?
Jul
29
accepted How is a cathode ray tube different from beta minus radiation?
Jul
29
comment How is a cathode ray tube different from beta minus radiation?
Great answer, thank you very much :)
Jul
28
comment How is a cathode ray tube different from beta minus radiation?
What is the maximum energy that an electron can carry when being the result of Beta decay?
Jul
28
comment How is a cathode ray tube different from beta minus radiation?
FYI: Electron beams are being used for radiation therapy, but I don't know to what extent. See Electron therapy or the famous Therac 25 that killed a few people because of faulty programming.
Jul
28
awarded  Scholar
Jul
28
comment Radioactive decay, why such unintuitive formula?
I'm afraid that I don't understand it, and I guess I just don't have the prerequisites to. But thanks in any case :)
Jul
28
asked How is a cathode ray tube different from beta minus radiation?
Jul
28
comment Radioactive decay, why such unintuitive formula?
I think you misunderstood me, because I already understand what you tell me in your comment. I restate my point: If $N_0 = 10$, $\lambda = 0.1$ and $\Delta t=1$, then you get 9.048. Whereas $(1- \Delta t \Lambda) = 0.9$. Those two numbers are simply not the same. With higher values of $\Delta t$ the difference is greater.
Jul
28
comment Radioactive decay, why such unintuitive formula?
hat is only true for sufficiently small $\Delta t$. I understand the concept of exponential growth, as in the bank. But in fact the bank uses the formula that I prefer
Jul
28
awarded  Student
Jul
28
comment Radioactive decay, why such unintuitive formula?
Thanks, but I do understand the derivation. I just don't see why the former formula is preferred in textbooks when the latter to me (and my co-students) seem much more intuitive. In fact even my teacher accidentally said that after one time unit a fraction of $\lambda$ will have decayed, which is only true if the time unit is defined to be sufficiently small.
Jul
28
comment Radioactive decay, why such unintuitive formula?
Yes, k will depend on the size of the time unit used. But so does $\lambda$, since $\lambda = -ln(1-k)$. Right?
Jul
28
revised Radioactive decay, why such unintuitive formula?
fixed typo in second formula