# Search results

1. ### Direction of friction: deceleration and turning

Thank you for your taking the time to write a reply, Doc Al! :) I should warn you: I'm not good at understanding physics, but if I don't understand it, then unless a problem looks identical to the one before, I'm at a bit of a loss, so here's hoping that I can develop this "physical intuition."...
2. ### Direction of friction: deceleration and turning

Hi! :) I'm confused about the direction of the friction vector when we decelerate and when we turn. I've memorized the directions (if I decelerate going east, friction is aimed west; if I am in a flat circle and going around it, friction points to the middle), but they don't exactly make sense...
3. ### Enthalpy equations with pressure/volume assumptions

I'm trying to learn the various equations of enthalpy with certain assumptions, but I couldn't understand where they came from. So, I tried to derive them myself, but now I'm lost beyond reason. I'm getting confused between the various forms of the enthalpy equation, depending on constant...
4. ### Heat engines: how can we yield work?

Thank you all for your replies: I'm getting closer in understanding! Right! :D The area under the PV curve is equal to the work done: I do get that. What I didn't get was why the second curve (for the compression) is a different curve than the original one. Thank you, Andrew Mason: I now...
5. ### Heat engines: how can we yield work?

So, I'm studying for the MCAT. There..I've said it. :) But, it's not a homework question: I just don't understand the concept. My study book's thermodynamics section includes a very rough sketch of a heat engine to describe the 2nd Law of Thermodynamics. A side note in the text says that if...
6. ### Find capacitance from time, power, and voltage

Ohhhhh, OK, right, right, right. We just went over those exponential curves today. That makes sense: it wasn't 16.67 amps at the very beginning. Whew...all right; thank you! ~Ibrahim~
7. ### Find capacitance from time, power, and voltage

Energy delivered to that stored on the capacitor....the U = .5QV formula! No: I just tried it and it worked!!!!!!!!!!!!!! This time, instead, I got .06 coulombs as the charge, twice the charge compared to my previous attempt. I completely forgot about that one. But, out of curiosity, why did...
8. ### Find capacitance from time, power, and voltage

1. Homework Statement A flashlight uses 6.0J in 1.8ms (0.0018 seconds). First question: find the power. Got it: 3333W (3.3E3 with two sig figs, which is the accepted answer in the online system). The real problem: find the capacitance if the flashlight uses 200V. 2. Homework Equations...
9. ### Work = -delta U

Oh, crap. Friction is a non-conservative force: it depends on the path. There are no conservative forces acting, only non-conservative (friction). 0J = 0J. Got it. Thanks for the solution, however simple! ~Ibrahim~
10. ### Work = -delta U

1. Homework Statement Work done by conservative forces = -\DeltaU 2. Homework Equations Above. 3. The Attempt at a Solution Here is the whole equation: Wc+ Wnc = \DeltaK. Wnc = \DeltaK + \DeltaU. So, Wc = -\DeltaU. But, for example, how does that apply in a...
11. ### Boron Neutron Capture Therapy (B10->B11)

Hmm...well, I actually don't speak Turkish. :( From what Google Translate tells me, yeah, you're right. There aren't too many resources online which is the reason why I created this thread. I would try looking through this thread. Is this for a homework assignment? What information do you...
12. ### Boron Neutron Capture Therapy (B10->B11)

Do you have any specific questions? Have you looked at the Wikipedia page for it? MIT has an oldish page on it, too. ~Ibrahim~
13. ### Equilibrium Titration?

Whoops, you're definitely right. :redface: It's a .05M solution that they took 25ml, not a .1M solution. Good call. I guess you titrated it a bit too much because, even though they're close, I'm guessing that it has a K>1 so the equilibrium concentration would have been even lower...
14. ### Term Paper: Is the brain immunologically privileged?

Re: Term Paper: "Is the brain immunologically privileged?" :) Ooh, yeah. :D Those sound good! I did a project on boron neutron capture therapy a while back (it was legit made awesome by none other than folks here at PF!) and it was a way to bypass the blood brain barrier. Definitely very...
15. ### Equilibrium Titration?

Oh, no, it's definitely OK. Another set of eyes always helps. :) I think it took 25ml of a solution of a .1M Ag+/.1M Fe2+. So, .100 mols/1000ml x 25ml = .0025mols of Ag+ initially, .0013mols @ equilibrium. ~Ibrahim~
16. ### Half-cell method

Hey, I just did this in class like two days ago! :) All right, I need a little background. How much do you know? Oxidation vs reduction? OILRIG? Anything? The quick way: Find out what's oxidized and what's reduced: calculate the oxidation # for each atom in the reactant side and then compare...
17. ### Term Paper: Is the brain immunologically privileged?

Re: Term Paper: "Is the brain immunologically privileged?" Ooohh, I have an idea. Are we talking blood brain barrier, etc.? You could do a topic on brain cancer and the effectiveness of treatments due to the BBB? ~Ibrahim~
18. ### Equilibrium Titration?

All right...I've never helped anyone on here before (usually I'm the one asking for help!), but let's see here: 3C) Yes, all products are [0.00] at the very start of a reaction. All right, let's go through all of problem 3. The first question of 3A is correct: (.10moles/1000ml) x 13ml =...
19. ### Boron Neutron Capture Therapy (B10->B11)

Beautiful! :D : D :D Thank you for this bit so much, I barely fit it in, but it's all good! I think my teacher really liked it! He was pretty impressed, too, which is a good thing in itself. 2.7MeV sounds just about right. :) Thanks again for all the help, guys: absolutely amazing! ~Ibrahim~...
20. ### Boron Neutron Capture Therapy (B10->B11)

I hate to bump this thread, but if anyone knows the answer to this last question, that would be splendid as the presentation is tomorrow at 12:40PM. But, nonetheless: thanks a ton, guys. I really appreciate the help, yet again. You help poor ignorant people like me, and truth be told, I'm...
21. ### Boron Neutron Capture Therapy (B10->B11)

Thank you for the reply, :) What is this site talking about then? http://web.mit.edu/nrl/www/bnct/info/description/description.html I mean, the image says that you get B11 for about ~10^-12 seconds...I just don't understand what makes that "B*11" different from a "B11" atom. Like why...
22. ### Boron Neutron Capture Therapy (B10->B11)

All right, I think neutron therapy is different from neutron capture therapy. Neutron therapy seems to be like "regular" therapy where the radiation attacks the cell's DNA. Neutron capture is something "picking up" a neutron and then kind of blowing up inside the cell: no DNA needed. But, it...
23. ### Boron Neutron Capture Therapy (B10->B11)

OHH..... Huh, well, that helps! :) Thanks, ~Ibrahim~
24. ### Boron Neutron Capture Therapy (B10->B11)

Hi! I hope I've posted this in the right section, but it definitely deals with the nucleus, so here goes. I'm doing a presentation on Boron Neutron Capture Therapy, which, if you don't know, puts boron inside tumor cells, shines a neutron beam onto those cells, which causes the boron inside...
25. ### Questions about fusion (from a high-schooler)

Right, but we'd need to find a source, like vanesch says. That makes complete sense, I kind of forgot you'd need energy to make anti-matter (with the matter to go with it). Well, let's hope we don't need to drop any more atom bombs, lol... ~Ibrahim~
26. ### Questions about fusion (from a high-schooler)

Hehe, thank you. Oh, I'm sure it is much more in-depth than this, though. I feel like I've only touched the surface. Still very excited and a bit let down that many people quickly ignore nuclear power, I mean, fission is still really nice! :) I think I get it: higher temperature, which means...
27. ### Questions about fusion (from a high-schooler)

Interesting, interesting. Ah, have the lithium on the walls and go down a drain near the bottom. Wouldn't the lithium absorb the energy from the neutrons and actually transform into tritium? Or does that not happen with liquid lithium? It is a concept, so... I'm almost finished with the...
28. ### Questions about fusion (from a high-schooler)

Wow, thank you so much. That information is great, I can't imagine getting that somewhere else. Those are the questions that articles seem to gloss over. That equation is definitely going into the PowerPoint, lol. :) I have one quick question about inertial laser confinement. How exactly are...
29. ### Questions about fusion (from a high-schooler)

Ahhhhh....So increasing one increases the other, so to speak? I think I get it. Well, I'm about finished with the section on magnetic confinement (my main area), so I'm going to do a few slides on inertial-laser confinement and then maybe one on inertial electrical. I have more time than I...
30. ### Questions about fusion (from a high-schooler)

Excellent, thank you. And this is the same heating that is done to raise the plasma to 10 million Kelvin, right? That is what I've read, just want to confirm. Now, from all the articles I've read, few seem to mention pressure. Doesn't fusion require extremely high pressure? Or is that already...