Homework Help

[Suukorak 354]

Hey, I'm new here, but I'm a good student and would be happy to help with anything I can. I'm a sophomore Mechanical Engineering major, so I can help with some engineering courses. I can handle up to college-introductory physics and mathematics as well, and I'm good at English (writing, spelling, proofreading, etc.) and I have studied French from elementary through high school. Let me know if I'm needed! I'm in whichever time zone New York City occupies (I don't remember their names offhand).

 

Suukorak

[SCS 7,443]

I doubt if anyone here will need help with Vector or Tensor Calculus, but hey, you never know. I guess i could help with Physics, Chemistry, Calculus, Algebra, or any other math related subject. (if you haven't already guessed, I LOVE math)

 

Can you help me with multivariable calculus and differential equations? I already have a strong knowledge of everything up through calculus 2.

 

When it comes to calculus 3, right now I only have a grasp on the very basics of 3D functions/graphs/mathematics, partial derivatives, directional derivatives, gradients, and double integrals. 

 

I could use some help with the following for calculus 3:

• Parameterization of 3D surfaces

   

• Symmetric equations for 3D surfaces

   

• A deeper understanding of directional derivatives, gradients, and the relationship between the two

   

• Vector calculus: divergence, curl, laplacian, Greens' Theorem, Stokes' Theorem, etc

   

• Line, Surface, & Triple integrals

   

• Cylindrical & spherical coordinates

   

• Jacobian and other applications of matrices to calculus, as well as the basics of linear algebra (including eigenvalues, eigenvectors, and so on)

   

• Differences between different 3D coordinate systems (I know this is really basic, but I'm still don't fully grasp it)

 

In regard to differential equations, my knowledge doesn't extend far beyond the basics. I could use help with some of the more advanced techniques for first and second order ordinary differential equations:

• Integrating factors

   

• Laplace transformations

   

• Application of infinite series to solving differential equations

 

An introduction to partial differential equations would be cool as well, as would an introduction to the formalisms and theory (in terms of formal proofs) behind calculus.

 

 

If you can help me with any of this, that'd be awesome.

[Starlight Fan 538]

Can someone proofread my French speech? It's about my family and it's supposed to last for one minute.

 

Ma famille est harmonieuse et tendre, je n’ai pas des freres ou des soeurs mais l’amour de mes parents est suffisamment. J’ai trois tantes et elles sont tres attentionné et elles souvent achetant des affaires pour moi. J'ai aussi deux oncles, mais je prefere mes tantes. Elles sont des soeurs de ma mere et elles sont tres aimable exactement comme ma mere. Ma mere est une femme independent et confiant. Mon pere est tres obligeant aussi. Ils souvent discutent avec moi et nous avons un bon relation. 

 

Also, for the last sentence, I'd like to say "my family has helped me a lot in my life, and I am very grateful." but I can't exactly translate that, so if someone could help me that'd be great.

 

Thanks!

Edited March 18, 2015 by Starlight Glimmer

[Tanos 179]

Ma famille est harmonieuse et tendre, je n’ai pas des fréres ou des seours mais l’amour de mes parents suffit. J’ai trois tantes et elles sont tres attentionné et elles souvent achetent beaucoup de choses pour moi. J'ai aussi deux oncles, mais je prefere mes tantes. Elles sont les soeurs de ma mere et elles sont tres aimable comme ma mere. Ma mere est une femme independent et confiant. Mon pere est tres obligeant aussi. Ils souvent discutent avec moi et nous nous entendons bien.

 

Edits: mostly took off some awkward wording and added the last phrase. Since this is an oral present the accent marks won't be graded. As for the conclusion, I think a good translation would be, "ma famille m'aidais beaucoup avec la vie et je suis tres reconnaissant". Edited March 18, 2015 by Tanos

[Starlight Fan 538]

Edits: mostly took off some awkward wording and added the last phrase. Since this is an oral present the accent marks won't be graded. As for the conclusion, I think a good translation would be, "ma famille m'aidais beaucoup avec la vie je suis tres reconnaissant".

Thank you for your help! 

 

 

filler for word minimum

 

[Suukorak 354]

 

 

 Can someone proofread my French speech? It's about my family and it's supposed to last for one minute. 

 

I would change a few more things.

 

 

 

 

Ma famille est harmonieuse et tendre, je n’ai pas des freres ou des soeurs mais l’amour de mes parents est suffisamment. J’ai trois tantes et elles sont tres attentionné et elles souvent achetant des affaires pour moi. J'ai aussi deux oncles, mais je prefere mes tantes. Elles sont des soeurs de ma mere et elles sont tres aimable exactement comme ma mere. Ma mere est une femme independent et confiant. Mon pere est tres obligeant aussi. Ils souvent discutent avec moi et nous avons un bon relation.

 

Ma famille est harmonieuse et tendre, je n’ai pas de freres ni de soeurs mais l’amour de mes parents suffit. J’ai trois tantes qui sont tres attentionnées, et elles souvent m'achetent des affaires. J'ai aussi deux oncles, mais je prefere mes tantes. Elles sont les soeurs de ma mere, tres aimable, comme ma mere. Ma mere est une femme independante et confiante. Mon pere est tres obligeant aussi. Ils discutent souvent avec moi et nous nous comprendons bien.

 

 

For the final sentence:

Ma famille m'a beaucoup aide dans la vie, et je suis tres reconnaissant.

@@Tanos, hope you don't mind if I used a few of your suggestions, and improved a few.

Good luck! 

[Tanos 179]

I would change a few more things.

 

 

 

Ma famille est harmonieuse et tendre, je n’ai pas de freres ni de soeurs mais l’amour de mes parents suffit. J’ai trois tantes qui sont tres attentionnées, et elles souvent m'achetent des affaires. J'ai aussi deux oncles, mais je prefere mes tantes. Elles sont les soeurs de ma mere, tres aimable, comme ma mere. Ma mere est une femme independante et confiante. Mon pere est tres obligeant aussi. Ils discutent souvent avec moi et nous nous comprendons bien.

 

 

For the final sentence:

Ma famille m'a beaucoup aide dans la vie, et je suis tres reconnaissant.

@@Tanos, hope you don't mind if I used a few of your suggestions, and improved a few.

Good luck!

 

No problem! However, the conclusion should be in the imperfect as it's a less defined period of time that hasn't ended (unless we're dead )

[Suukorak 354]

@@Tanos, good point. Though it would have to be "ma famille m'aidait," because that's how you conjugate it in third person (the subject being "ma famille"). Somehow it still feels more natural to me in passe simple. Unless you wanted to just use the present?

Sorry, I'm a little rusty in French, I haven't studied it in... dang, must be nearly two years now.

[Tanos 179]

@@Tanos, good point. Though it would have to be "ma famille m'aidait," because that's how you conjugate it in third person (the subject being "ma famille"). Somehow it still feels more natural to me in passe simple. Unless you wanted to just use the present?

Sorry, I'm a little rusty in French, I haven't studied it in... dang, must be nearly two years now.

All's good. French can be irritating for the aspects that are unusual since most of it is cognates or nominally similar grammar.

PS: diggin' the kopaka profile pic

Edited March 18, 2015 by Tanos

[Pastel 7,627]

Can someone proofread my French speech? It's about my family and it's supposed to last for one minute.

 

 

Also, for the last sentence, I'd like to say "my family has helped me a lot in my life, and I am very grateful." but I can't exactly translate that, so if someone could help me that'd be great.

 

Thanks!

 

Ma famille est tendre et en harmonie, je n’ai pas de frère ou soeur mais l’amour de mes parents est suffisant (or "me suffit"). J’ai trois tantes, elles sont très attentionnées et elles achètent souvent des affaires pour moi. J'ai aussi deux oncles, mais je préfère mes tantes. Elles sont les soeurs de ma mère et elles sont très aimables exactement comme elle. Ma mère est une femme indépendante et confiante. Mon père est aussi très obligeant. Ils discutent souvent avec moi et nous nous entendons bien.

 

Last sentence: Ma famille m'a beaucoup aidé dans ma vie, et je leur en suis très reconnaissant.

Here you go. Am I too late?

Edited March 18, 2015 by Blobulle

[Cosmik Vek 764]

Hey guys, this is for my english communication class course and I need at maximum and minimum 20 respondants for a survey about the internet and I need results for tomorrow! (absolutly no money involved)

It would really help if you could respond to it!

Once I will reach 20 people then I will tell everyone that it's over and I will remove the link.

https://www.esurveycreator.com/s/f5f7e3f

Thanks!

[CloudKicker 391]

can i enter it please i would really like to try these out 

[Misty Rose 3,215]

I'll be coming to this thread once Algebra 2 starts hitting me hard this year

[SCS 7,443]

I'll be coming to this thread once Algebra 2 starts hitting me hard this year

 

I can help with any math up through the basics of calculus 3, so I'd be happy to help you or anyone else with math.

[Misty Rose 3,215]

I can help with any math up through the basics of calculus 3, so I'd be happy to help you or anyone else with math.

I'll be sure to come to you then Thankies!

[Admiral Regulus 2,769]

I have a problem.

 

Imagine a ball on a circular table. This friction between this table and the ball is negligible. There is a hole in the center of the table. A string is attached to the ball, and this string goes through the hole. Now, let's suppose the ball is rotating on the table with a constant velocity. You're holding on to the other end of the string from under the table, and this force keeps the ball from flying off.

 

So, here's the question. Suppose you pull the string down, and in consequence, the ball gets pulled in to the center of the table. What is the work needed to accomplish this?

 

 

If my understanding is correct, there is no torque acting on the ball, so angular momentum is conserved. This means that the ball's rotational speed increases as it's pulled in. When the rotational speed increases, the force required to pull the ball in increases. This means the amount of work needed increases.

 

Putting everything together, what I'm getting is that the rotational energy of the ball KE = 1/2 I * ω² approaches infinity as the radius of the ball's trajectory approaches zero. Using the alternative method of W = ∫ F * dr also yields the same result, considering that F = m v² / r and v = constant / r. This means an infinite amount of work is needed to pull the ball in. But this... this just can't be right. =/

 

[Suukorak 354]

@@Admiral Regulus, this is an interesting question. Thinking about it, it seems to me that if you let go of the string, the ball would go off in a straight line. In that case, angular momentum would not be conserved - or rather, it would be conserved around the center of mass, which would be close to the center of the ball, I presume. In that case, the angular momentum would be the rolling of the ball, not its movement around the hole in the table.

So instead, what if linear momentum is conserved?

 

In this case, we still get that angular momentum goes to infinity, but linear momentum does not; in fact, mv² stays constant. However, (integral of) F dr still goes to infinity since F=mv²/r and r goes to 0.

 

Or what if neither momentum is conserved?

 

This gives me a weird result, but it might be right. In this case, the work would be the difference between the rotational energy of the ball spinning in place and the original rotational energy. But this makes the work negative, for some reason.

 

For the moment, I guess, I don't know.

I'll go think about this, discuss it with some people I know. I'll get back to you if I have a better answer.

[Nit Pick 247]

I'm in need of some help with ADA compliance or something along the line of logo design.

 

I got some Photoshop and Illustrator skills and currently learning InDesign.

[Suukorak 354]

@@Admiral Regulus, all right. I used my contacts (wow, I sound like a spy when I say that!) and there is an answer.

 

Our saving grace is that this is a ball and not a point-mass. If it were a point mass, the work really would be infinite. But it's not. Instead:

1. We are exerting no torque on the ball, so its angular momentum is conserved.

2. The ball has an initial energy of I₁w₁²/2, where I₁ is calculated using the center of the table as the axis (obviously).

3. At the center of the table, the moment of inertia I₂ is that of a sphere revolving around a central internal axis.

4. Since angular momentum is conserved, we can find a final angular velocity w₂ for when the ball is centered at the center of the table.

5. We can then calculate the final energy I₂w₂²/2.

6. The work done is therefore the difference of these two energies.

I forget the formulae for moments of inertia right now, but it's easily looked up.

 

 

Good luck!

[Admiral Regulus 2,769]

@@Suukorak,

 

Yep. Pretty much.

 

Considering that we haven't studied rigid bodies in this class yet, we're supposed to model everything as a point mass. So... I was right. I think I just misread the problem. In the part before it, an inner radius was specified. Then it asked me to find "the work done to pull the ball in." I was assuming "pull in" meant to the center. My professor probably meant to say "pull it in to r = 2," which is a calculation that yields a real result.

 

You just watch, I'm gonna lose like 20 points for this.

[Suukorak 354]

 

 

You just watch, I'm gonna lose like 20 points for this.

Oh, they had another radius. Okay, that would work too. That's probably how I would read the question, in fact. So I think you'll get your points.

[#1FluttershyFan 206]

I can help with grammar or english stuff as well as science (assuming there's not too much math involved).

PM me if you want help.

Edited March 24, 2015 by #1FluttershyFan

[Starlight Fan 538]

 

 

Ma famille est tendre et en harmonie, je n’ai pas de frère ou soeur mais l’amour de mes parents est suffisant (or "me suffit"). J’ai trois tantes, elles sont très attentionnées et elles achètent souvent des affaires pour moi. J'ai aussi deux oncles, mais je préfère mes tantes. Elles sont les soeurs de ma mère et elles sont très aimables exactement comme elle. Ma mère est une femme indépendante et confiante. Mon père est aussi très obligeant. Ils discutent souvent avec moi et nous nous entendons bien.

 

Last sentence: Ma famille m'a beaucoup aidé dans ma vie, et je leur en suis très reconnaissant.

Here you go. Am I too late?

No, my speech is tomorrow. (I couldn't see this cause I didn't have my computer) but thank you and everyone else who helped with my speech

[Knight Hadron 372]

Hey, got a math question for y'all.

 

In triangle ACD, B lies on AC, E les on CD, and BD and AE intersect at F. AB:BC=17:13 and AF:FE=16.34:11.69. If DE=k(CE), find k.

 

This is a question from a past test, and therefore I have the answer, but no solution of how to get the answer. Any help would be nice. I think you could solve this using mass points but I don't really have a grasp on that concept; while I'm here I might as well ask, how do you use mass points?

 

The answer is 14.52, rounded to 4 sig figs.

[Moonyshy 86]

um, hello! i am a 2L student at a law school. soon, i will be graduating! i have much experience in immigration law though! if maybe you have English homework, history homework, or any homework related to law stuff, i would love to help however i can! please send me a message c: i will try my best for you.