T Nation

Please Help Me with Physics

I’m not asking you to do my homework, only to help me find where I’m messing up.

Here is how one guy did it, but I couldn’t follow his notation:

This is how I attempted it:

If particle 3 is to remain stationary, then the force on particle 3 from particle 1 must equal the force from particle 2 on particle 1.

Using coulombs law to state this:

F=[K(q1)(q3)]/(r^2) = [K(q2)(q3)]/(r^2)

But, particle 3 has to be to the right of particle 1, if it was in the middle between particle 1 and particle 2, then it would be pulled to the left towards particle 2, because particle 1 would repel particle 3 to the right, and particle 2 would pull particle 3 left.

So to make up for this in our equation we make the distance from charge 2 to charge 3, “R+L” where r is the distance between charge 1 and charge 2:

F=[K(q1)(q3)]/(®^2) = [K(q2)(q3)]/((r+L)^2)

Now we can place some numbers in this equation, and solve for L:

F=[(8.99x10^9)(3.5x10^-6)(5.5x10^-6)]/((.0024)^2) = [(8.99x10^9)(-4.0x10^-6)(5.5x10^-6)]/((.0024+L)^2)

Coulombs constant and Q3 cancel from the equation, so I’m left with

F=[(3.5x10^-6)]/((.0024)^2) = [(-4.0x10^-6)]/((SQRT(.0026)+L)^2)

(I know that the two original particles are SQRT(.0026) m apart)

So now we have an equation with only one unknown, L, so I solved the equation for L and got that L was .03765662 meters.

So we now know that particle 3 is 3.765662 CM from particle 1.

We can add that to the original coordinates of particle 1, to find out where particle 3 is:

the angle that these three particles lie on is -11.3

x= 3.765662cos(-11.3) + 3 cm = 6.692663 CM
y= 3.765662sin(-11.3) + .5 cm = -.2378669183 CM

However the online grader says that those are both wrong. AND I ONLY HAVE ONE ATTEMPT LEFT TO GET CREDIT

You do physics like Eminem.

If you lose your virginity, I give you a 700% greater chance of getting this right.

I love that this is all on a bodybuilding forum.

So you’re telling me that you were doing your online homework, got stuck, and then though, “Hey! Why don’t I post this on T-Nation, a bodybuilding website!”.

Not trying to be a dick here, but why don’t you just ask someone in your class? This is a great excuse for some late night “studying” with hot classmates.

[quote]hungry4more wrote:
If you lose your virginity, I give you a 700% greater chance of getting this right. [/quote]

I humbly disagree. Keping your virginity is the only way you’d have any hope of being able to complete it.

I’ve been a Star Trek fan for close to 24 years…I became one when I was 13. There was a noticeable decline in my interest that started the very moment I lost my virginity. I still like it, but certainly not as strongly.
That day was yesterday.

Geez, I thought you were the be all, end all, smartest guy on the planet. Can’t believe you’re asking for homework help.

[quote]jahall wrote:
So you’re telling me that you were doing your online homework, got stuck, and then though, “Hey! Why don’t I post this on T-Nation, a bodybuilding website!”.

Not trying to be a dick here, but why don’t you just ask someone in your class? This is a great excuse for some late night “studying” with hot classmates.[/quote]

logs on to www.physicsnation.com

“Hai gais! How can I get big and strong?? Thanx. Byeee!”

[quote]Nards wrote:

[quote]hungry4more wrote:
If you lose your virginity, I give you a 700% greater chance of getting this right. [/quote]

I humbly disagree. Keping your virginity is the only way you’d have any hope of being able to complete it.

I’ve been a Star Trek fan for close to 24 years…I became one when I was 13. There was a noticeable decline in my interest that started the very moment I lost my virginity. I still like it, but certainly not as strongly.
That day was yesterday.[/quote]

Wtf no no no, see sex motivates you to be smarter and more awesome, because that gets you more sex! Unless you have a uni-brow obviously.

[quote]Nards wrote:

[quote]hungry4more wrote:
If you lose your virginity, I give you a 700% greater chance of getting this right. [/quote]

I humbly disagree. Keping your virginity is the only way you’d have any hope of being able to complete it.

I’ve been a Star Trek fan for close to 24 years…I became one when I was 13. There was a noticeable decline in my interest that started the very moment I lost my virginity. I still like it, but certainly not as strongly.
That day was yesterday.[/quote]

No, if he loses his virginity then he’ll understand a very basic law of physics that will catapult him forth in his education: what goes up, must come down.

And then come again after he fails to satisfy her the first time.

[quote]Nards wrote:
I love that this is all on a bodybuilding forum.[/quote]

x2 x Planck’s constant x mc^2.

I hated Electrical Systems Engineering in University, I did only one semester and thought I’d fail it like 40% of the other kids. Superposition theory…ewwww.

[quote]attydeb2005 wrote:
Geez, I thought you were the be all, end all, smartest guy on the planet. Can’t believe you’re asking for homework help. [/quote]

Yeah, really Jindatale. You ridicule and belittle the intellect of virtually every person on this site in the SAMA forum, all of whom were giving you serious advice of the highest and most important order, and then you turn around and ask us for help with your fucking HOMEWORK!?!?!?! You cannot be SERIOUS!

[quote]jdinatale wrote:
I’m not asking you to do my homework, only to help me find where I’m messing up.
[/quote]

Get a Tutor. Ask Charlize if she’s available.

http://www.youtube.com/watch?v=_-agl0pOQfs i used to have questions about physics, but that video answered them all!

Have you tried solving the problem while sitting under an apple tree?

V

I just took this last semester and somehow got a B. If you are having trouble with Coulomb’s Law though, you better start going to review sessions real fast. It’s going to get MUCH harder.

The correct answer is that particle 3 should fuck off and stop trying to break up particle 1 and 2, who have been together for like 6 months. Particle 1 is a real volatile motherfucker and will pimp-slap the shit out of particle 3 if he keeps stepping up in this bitch.

Also, Coulomb is a dick.

Why is everyone bitching? People post math questions on here all the time and they don’t get flame-raped.

[quote]PimpBot5000 wrote:
The correct answer is that particle 3 should fuck off and stop trying to break up particle 1 and 2, who have been together for like 6 months. Particle 1 is a real volatile motherfucker and will pimp-slap the shit out of particle 3 if he keeps stepping up in this bitch.

Also, Coulomb is a dick.[/quote]

mmf?

oh wait…

[quote]Sick Rick wrote:
Why is everyone bitching? People post math questions on here all the time and they don’t get flame-raped.[/quote]

Go to the SAMA forum and read the “First Date at 19” thread. I think that’s what it’s called, something along those lines. Maybe that was Herc’s. Anyways, just look for his post in SAMA. He started it a few weeks ago. It will explain everything.