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Alright, I ended up with A=+/- 1 and B=1/sqrt(2).

Ahhh yes. I understand! Thank you very much :)

I keep getting that phi is zero.

The second derivative is phi''=-2AB^2tanh(Bx)sech^2(Bx)= -2AB^2tanh(Bx)+2AB^2tanh^3(Bx) and so tanh(Bx)[2AB^2-A]+tanh^3(Bx)[-2AB^2+A^3]=0

d^2phi/dx^2= -2AB^2tanh(Bx), correct? Now I have gotten the equation tanh(Bx)[2AB^2-A+A^3tanh^2(Bx)]=0 I set 2AB^2-A+A^3tanh^2(Bx)=0 tanh(Bx)= sqrt[2B-1]/A But now what? Was I supposed to change the tanh^2(Bx) into 1-sech^2(Bx)?

Homework Statement Okay, here's the deal: I have been given a second order nonlinear differential equation, and I have also been given the general solution with constants A and B. I am supposed to find the constants A and B. The solution represents a fermion at rest, since the solution does...

Hello! I am wondering if anyone can help me decide what to do about this problem. I'm at a college majoring in physics, and I'm almost done with my two years. I'm applying to different universities,and I have a professor that wishes to write me a recommendation for when I transfer. He asked me...

I am talking about first order ones.. I don't know how to solve second order ones.

Is the derivative of a function a differential equation? I guess it would be because it involves a derivative, right? Would the solution to the equation just be the original function? Is solving a differential equation just another way of integrating? Like with finding solutions of separable...

Thanks a lot. I didn't know it was so complicated. Thanks again.

Homework Statement A ball starts from rest and rolls down a hill with uniform acceleration, traveling 130m during the second 6.0s of its motion. How far did it roll during the first 6.0s of motion? Homework Equations I guess: v=v(0)+at v^2=v(0)^2+2ay x=x(0)+v(0)t+0.5at^2 The Attempt at...

Ouuuu interesting. Thank you :)

Thanks!

Homework Statement Hi! I am doing some problems to practice for a math competition, and I'm wondering if I did this correctly. I don't really have an answer sheet, so I have no way of knowing whether I'm right. If you would please review it, that would be cool! It reads: There are...

Hello! I'm wondering if anyone knows any universities in France that have a great physics department. I'm currently in my second year of college getting my associates degree, and I'm looking at options in France for my bachelors. My French professor is always talking about French...

Uhm, okay. So... who is right? I don't quite understand what L-ε < f(x) < L -ε means. Do you mean L - ε < f(x) < L + ε ?

Homework Statement Use a graphing calculator to find \delta when 0<|x - \pi/2|<\delta and |sin(x) - 1|<0.2 Homework Equations I don't think there are any other than the format of the previous information: 0<|x-a|<\delta and |f(x)-L|<\epsilon The Attempt at a Solution Okay...

Oh, okay! Thank you very much! :)

Homework Statement The question wasn't really written down. It was a question asked after an explanation, and it really wasn't straightforward. I'm going to try to make it into a intelligible thing. If there is a +3 charge and a -1 charge at a distance from one another, where to the right...

Oh my god! Yes! I see! Thank you! I wonder why my teacher did it like that, though. Thanks! :)

In that case, j would be just four, right?

Hmm well.. that's how my professor did it. So after trying multiple times with different values for n and j, I got the right one. I ended up using n=7 and j=4. At first I tried n=14 and j=8. Nope. Then, I tried n=14 and j=4. Nope. Then, I tried n=7 and j=4! It worked... I'm still not so sure...

Homework Statement Find the coefficient of x8 in the expansion of (x2-3)7 Homework Equations This one: (n n-j) an-jxj The Attempt at a Solution Hi! Well, I know that x= x2 a= -3 n= 7 and apparently, j=8. This is what confuses me. n-j is a negative number.. how would...

Thank you so much :) I'm going to check it out :)

Hello! I've recently begun to read a lot of nonfiction books. I'm currently reading a book about stories told by Richard Feynman about his amazing life. It's hilarious and so clever. I would absolutely LOVE to read a book on the history of physics! I think it's really fascinating. Could...

I mean, I think it would be equal.. but I'm not sure. Apparently it would be zero if the string has negligible mass.

Homework Statement If there is a mass on a frictionless table connected by a string to another mass hanging from a pulley off the side of the table, is the net force on the string zero? Is the force of tension equal on both sides if the system is accelerating? Would both objects accelerate...

Hmm... Everyone I know at my school avoids math like if it were a disease. If I take them separate, I'd pay around a hundred dollars more. I'm guessing that wouldn't be much of a problem. Yeah, I totally need to take them. I'm thinking of taking both separately. I need to take them in the...

Hi! I am currently taking a math class called college algebra. Here's the little description thing: MAC1105 - This course introduces the student to the concept of functions and their graphs. Students will graph linear, quadratic, rational, exponential, logarithmic, radical, power, and...

I don't understand that, but hopefully in the future I will.. I guess if the object is on the surface I would just use mg, but if the object is far from the surface I'd use GmM/r^2 ?

Okay I just tested it with a 60 kg person and both were the same!

So will the weight using mass times the local acceleration of a person on the surface of the Earth be the same as the weight found using the universal gravitation? How would I know which to use?

Wow.. Just.. Yep. Thanks

But there really is gravity, right? Or is there no gravity because he has no way of telling that there's no gravity? Is that what 'reference frames' refers to?

Ooh, okay. So it's not really weightless.. it just feels like it is. So a scale would read zero but only because there's no normal force? Wait but in space there is gravitational force.

Homework Statement If someone is in an elevator that is in free fall, why do people say that the person would be weightless? Wouldn't the person weigh mass times the gravitational acceleration?

Omg. So the answer for a=9.48 m/s^2 right?? I'm starting to doubt everything...

oh my. i almost died. i thought it was right and did my assignment based on it since no one had answered. thank you soooo much!

The height is the independent variable, right?..

So how would I put that into a= 2y/t^2 ? Can't I put it in and do 2*(1m/0.211s^s)?

Wait. What? So is 0.211s^2/m equal to 1m/0.211s^2? :/ So would I have 2m/0.211s^2 ?

Okay. I think I get it a little after thinking about it for a while. I used that equation and I moved it around to get a= 2y/t^2 If I were to put the slope there, would it work?? Do I have to somehow make the t^2 on the top?? Please help. is the slope the same thing backwards?? oh my god if...

I don't know. I really don't know how to change it. I have no clue and I can't even think of anything close because I simply don't know. I can't come up with something out of nothing.

oh. my. god. Yeah, I didn't realize that. I still don't get it, though. I have the slope of the line.. and I have different heights, but I only need one answer for the acceleration that counts for everything.

How could that even be? I don't even know the initial velocity.

...? Does that mean y=y0+v0t+1/2 at2 That's the only one I know that has initial height..

Uhm, I don't understand.. So we basically did this in class and we set it up and timed it. We did it multiple times with different heights and then we graphed the data. But it was a quadratic relationship so we were told to use the average time to find time squared and then graph time squared vs...

Homework Statement I have a graph of time squared vs. height. It shows the relationship between the height of a ball and how long it takes for it to fall, squared. I don't have this in the form of a question, but I need to use the slope, which is 0.211 s^2/m, and turn it into a value for...

Really!? So I am right.. I was told by someone that part C was wrong.. o_o

Homework Statement A projectile is fired from ground level at time t=0, at an angle of θ with respect to the horizontal. It has initial speed V0. Part A Find the time it takes the projectile to reach its maximum height. Express in terms of V0, θ, and g. Part B Find the time at...