Recent content by Badger

To dynamic, By dimensional analysis so far: N = Q / K = [Joules]/[Joules/decay] = 1.25*10^17 [nuclie decay] N_0 = (.0013 kg) / (3.70*10^-25 kg/atom) = 3.51*10^21 [atom] = ?[nuclie decay] t_(1/2) = 987552 [seconds] N = N_0 (.5)^[t/(t_.5)] ln (N/N_0) = t/t_.5 ln (.5) t = [ln (N/N_0) /...

to dynamic... I think your right. but even then with the new number I still get a wrong answer. to kurdt... I recalculated everything and stored it as exacts... maybe I didn't follow you correctly. Q = MCT = 119666.4 J {this is definitely correct} K_alpha_decay = 9.58*10^-13 J {also correct...

Thanks again but I think the units are confusing me here. lambda = r = 1 / T = ln 2 / t_(1/2) = 7.02*10^-7 [1/second] N = 1.30 g 223^Ra * 1 mole / g * atom / 6.022*10^23 mole = 9.68^-27 atom. 1 atom has 1 nuclei ? so N is the same number nuclei as atoms? A = rN = 9.68*10^-27 nuclei decay /s ...

This isn't working out. The energy output for the radium when calculated from MeV to Joules is 5.98023 MeV * (1*10^6 ev / 1 MeV ) * (1.602 *10^-19 J / eV) = 9.58*10^-13 J The thermal energy required to heat the .335 kg of water in the problem is 1.18 * 10^5 J The energy output from the radium...

Homework Statement The radium isotope ^{223}{\rm Ra}, an alpha emitter, has a half-life of 11.43 days. You happen to have a 1.30 g cube of ^{223}{\rm Ra}, so you decide to use it to boil water for tea. You fill a well-insulated container with 340 mL of water at 16.0^\circ {\rm C} and drop in...

Thanks that worked out flawlessly.

[SOLVED] Radioactive Dating with Potassium Argon Homework Statement The technique known as potassium-argon dating is used to date old lava flows. The potassium isotope ^{40}{\rm K} has a 1.28 billion year half-life and is naturally present at very low levels. ^{40}{\rm K} decays by beta...

doesn't seem like it... integrating the cos(2kx) part just gives me a sin function again and again I get an integer times pi within leading to more 0. right?

Homework Statement P = \int_a^b \, \left| \psi(x) \right|^2 \, dx If the particle in the box is in the second excited state (i.e., n=3), what is the probability P that it is between x=L/3 and x=L? To find this probability, you will need to evaluate the integral: \int_{L/3}^L...

Thanks you helped a lot

The distance between the i2 current and the left current is (d-(a/2)). (d+(a/2)) for the right current. I thought L was 'a,' the amount of wire running directly parallel of of l_loop. But that didn't work either.

Hello all, I thought I was starting to understand these magnetic field problems but this one is driving me crazy. I've inputted a good 6 or 7 answers and they all failed. Help would be awesome as always. Homework Statement A square loop of wire with side length a carries a current I_1...

I think I get what your saying. Point 1 @ L will have a up-right vector for B. Point 2 @ L will have a down-right vector for B. Both will be a hypetnuse of equal magninute. The y's will cancel. But I don't see how I determine the x-components that add up. I need angle an angle or at...

Hi, can someone help me out? I've tried 5 different solution that I thought were definitely right and they all give me the same response: "Your answer is off by a multiplicative factor." Homework Statement Find the magnitude of the net magnetic field B_L created at point L by both wires...

Homework Statement Let {\rm A} = \left(x_1,y_1 \right) and {\rm B} = \left( x_2,y_2 \right) be two points near and on the same side of a charged sheet with surface charge density + \sigma . The electric field \vec{E} due to such a charged sheet has magnitude E = \frac {\sigma}{2 \epsilon_0}...