Formula Definition and 1000 Threads

What's the definition of the "d" in that formula?

Hello, I'm going to build a solar-powered go-kart. To determine the sprocket that I want to use I need a formula to calculate the top speed which also considers vehicle weight and other resistance forces. All the formulas I found just used sprocket tooth and rpm to calculate top speed but of...

Homework Statement Sodium carbonate exists in hydrated form, Na2CO3.xH2O, in the solid state. 3.5 g of a sodium carbonate sample was dissolved in water and the volume made up to 250 cm3. 25.0 cm3 of this solution was titrated against 0.1 moldm-3 HCl and 24.5 cm3 of the acid were required...

1. The problem is: Which charge will a sphere have if it has a diameter of 0.26 meters and produces an electric field of 1030 N/C in the surface? 2. Gauss Law3. I need the charge of the sphere but i couldn´t find any formula to calculate the charge given the distance (r) and electric field (E)

My friend has asked me for a formula that will solve his kid's elevator game. Imagine an apartment building with an infinite number of floors, both + and -. You start on an arbitrary floor, say 11. The game asks you to meet your mother on the 61st floor (the actual goal floor changes). But the...

Homework Statement Menthol, the substance we can smell in mentholated cough drops, is composed of C, H, and O. A 0.1005-g sample of menthol is combusted, producing 0.2829 g of CO2 and 0.1159 g of H2O. What is the empirical formula for menthol? If menthol has a molar mass of 156 g/mol, what is...

Hello everyone! I am currently stuck at the two type of questions below, because I am not really sure what method should be used to calculate these question... Could you give me a hint how to do these questions? :(

Hi, we were rearranging formula to make $$x$$ the subject and for one equation our answer was different to our lecturers, but they failed to explain why they were right and we were wrong- if someone could that would be great. The equation with our working: $$y=5\left(x+3\right)$$...

Hello! I am trying to get to grips with the Bayes' formula by developing an intuition about the formula itself, and on how to use it, and how to interpret. Please, take a problem, and my questions written within them - I will highlight my questions and will post them as I add the information...

*Given Newton's Cooling formula, where T(t) predicts temperature, and where Te is the temperature of the enviornment, T[0] is the temperature when t = 0: T(t) = Te + (T[0]+Te)e^-rt predict Te when T(120)= 86.632 T(240) = 79.210 r = 0.001 I don't know how to even remotely go about solving...

Homework Statement Is there a minimum value for the total energy of the electron (in this analysis)? The previous parts: Use Larmor formula to find ##\frac{|\Delta E|}{K}##, where ##|\Delta E|## is the energy lost per revolution. the result is ##\frac{8\pi v^3}{3c^3}##. ##\frac{v(r)}{c}## was...

Hey! :o We have the sequence $$0, \ 2 , \ -6, \ 12, \ -20, \ \ldots$$ Its recursive definition is \begin{align*}&a_1=0 \\ &a_{n+1}=(-1)^{n+1}\cdot (a_n+2\cdot n)\end{align*} or not? How can we convert that in the explicit form? (Wondering)

Hello, Could someone help me find a general derivation of the formula for addition of capacitance of conductors? I'm hoping to find something that could be applied to a general assortment of conductors, not just parallel plate capacitors. I look forward to your response, Pete

Hello Everyone, I am brand new to this forum and I am currently doing "student research project task" where I need to conduct my own experiment basically. I am currently struggling to find a formula for an impact velocity. I hope there is someone in this forums that could help me. What I...

Hello. I am trying to decipher the formula, making sure I understand what exactly is going on in each part of the expression. I will be grateful for your guidance, corrections and help. Below I show the formula and the example for only 3 possible outcomes (in general it would be k) \(p =...

Hello! (Wave) Let $\phi \in C^1(\mathbb{R})$ and periodic. We consider the problem $u_t=u_{xx}, x \in \mathbb{R}, \ 0<t<\infty$, with initial data $\phi$. I want to compute a formula for a solution $u$ and I want to prove strictly that this formula solves the initial value problem. I also...

Hi. I am working my way through some complex analysis notes(from a physics course). I have just covered Cauchy's theorem which basically states that the integral over a closed contour of an analytic function is zero. this is then used to show that contours of analytic functions can be deformed...

I recently learned about Electric displacement field and capacitors, and I have a question that how was the formula derived shown below (blue circle part)? Thanks!

Just curious: Can I "recover" the analytic description ( say, like a Mathematical expression) from a graph? I just did well on a Sudoku recently . Please see below:

Homework Statement Homework Equations marginal revenue[/B] (R') is the additional revenue that will be generated by increasing product sales by one unit The Attempt at a Solution I don't know how to start. Q is the number of items sold at price x. y is the marginal cost, the cost of...

Hello everyone, Is there a proof that takes us from the sum idea of the volume: $$\sum_{i=1}^m \sum_{j=1}^n f(x_i,y_j) \Delta x \Delta y$$ To the integral idea: $$\iint_R f(x,y) dxdy$$ Or something that relates the volume to the integral just like The Fundamental Theorem of Calculus?

Hi, first of all sorry... I know (close to) absolutely nothing about physics except from what I remember from school a looong time ago... :-). So, my question might sound a bit silly here. But thanks a lot for taking you time already! Homework Statement In retail business there is some...

Hi there. I am working with a problem where a sequence of numbers arises. This sequence reads: ##\{0,1,3,5,10,15,21,28\}## as far as I have worked it. I am trying to figure out the underlying relation that gives this sequence. These are related to indexes in a matrix, and I am trying to...

Homework Statement What is another form of point slope formula Homework Equations Y = mx+b The Attempt at a Solution Y - y2 = m(x - x2) I’m not sure I’m trying to find B but I don’t know how

A comment by MarkFL in a https://mathhelpboards.com/pre-algebra-algebra-2/how-many-times-do-i-have-increase-3-a-24655.html#post110181 includes this formula: $$n=\left\lceil\frac{\ln\left(\dfrac{50}{3}\right)}{\ln(1.03)}\right\rceil$$ On my browser, that formula displays in a strange way...

I've been having a sign problem while deriving the permittivity formula using Drude model, and I found out that the problem came from the fact that complex field vectors are expressed with e-iwt, not eiwt, thus producing (-iwt) term when differentiated...

Suppose a comet F ,at 1 AU distance, is traveling toward a massive body (a neutron star or other) with v= .99 c, suppose also that a = 3 km/s^2 and (to simplify calcs) that it is uniform from there to the star. It will hit the star after ca. 1000 seconds and its speed should equal C: 297*10^9...

Little confusion regarding one line on Resnick's book! This says light dragged by refractive medium ok but how 'by the ether'? In the rest of the topic he says ether is stationary with respect to the observer(i.e. not dragged along by the water and that is how the Fresnel's exp. was explained).

Is there formula that transforms a matrix into its row-reduced echelon form? I know I can get there by row operations. But isn't there be like a formula?

In his article 'Quantum theory of radiation', Reviews of Modern Physics, Jan 1932, volume 4, Fermi gives the relativistic hamiltonian function ##W_a## for a point charge by equation (13), ## 0 = - \frac 1 {2m} \left( \left[ mc +\frac {W_a - ~eV} c \right ]^2 - \left[ p -\frac {eU} c...

If I have an investment, that is compounded at some rate ##r##, ##n## times per year, it can be written as a function as such: $$A(t)=P\left(1+\frac{r}{n}\right)^{nt}$$ My question is in regards to the 1 here. I think I have a general idea of what it's for, but I can't really put it into...

Hello! Griffiths is deriving the Abraham-Lorentz formula, which calculates the force that the radiation puts on a charged, accelerating particle (i.e. the force that makes it harder to accelerate a charged particle than a neutral one). For the non-relativistic case, the formula is...

using Rodrigues' formula show that $$\int_{-1}^{1} \,{P}_{n}(x){P}_{n}(x)dx = \frac{2}{2n+1}$$ $${P}_{n}(x) = \frac{1}{2^nn!}\frac{d^n}{dx^n}(x^2-1)^n$$ my thoughts $$\int_{-1}^{1} \,{P}_{n}(x){P}_{n}(x)dx = \frac{1}{2^{2n}(n!)^2}\int_{-1}^{1}...

I don't know why, but I have a slight ambiguity regrding the Rydberg formula. In some places it is written as : 1/λ= Rh(1/n12-1/n22) In some: E= -Rh(1/n2) In some: 1/λ= Rh*(z2/n2) At some: 1/λ= Rh*(z2)(1/n12-1/n2)2 Please tell me. Where these formula are used? Are they even correct?

Consider the pairing term in Weizsäcker formula. Here https://en.wikipedia.org/wiki/Semi-empirical_mass_formula#Pairing_term it is claimed that: I don't understand how Pauli exclusion principle should be the cause of this. This term comes from spin-spin interaction (or "coupling"), but I do not...

Hello, The problem I came up with deals with the structures that can be obtained by joining squares side to side or corner to corner. Specifically to this problem, structures, that are symmetrical to each other, are regarded the same. Ideally, I am looking for a formula that will tell how many...

I have included a screenshot of a part of my textbook that is giving me a slight bit of confusion. It's talking about how to get the formula for adding sines and cosines. The part that I am confused about is the very first formula introduced in the screenshot. From what I understand, we are...

Calculating for a section of an engines connecting rod that is always changing speed I have seen different formulas for inertia. Must be different types. Since it is changing speed I guess I am looking for the inertia that is against that change. any help is much appreciated. I know ya'll get a...

Hello! (Wave) I want to check by direct differentation that the formula $u(x,t)=\phi(z)$, where $z$ is given implicitly by $x-z=t a(\phi(z))$, does indeed provide a solution of the pde $u_t+a(u) u_x=0$.I have tried the following, but we do not get the desired result. Have I done something...

Hello I'm new here. Can someone please help me with the conjunctive normal form for this formula ? (((A -> (B -> C)) & (A -> B)) & A) <-> C I don't know if i did this right or not. If not what should i do ?

Hello everyone ! I'm working on my highway code and my book give me the approximate formula and the real formula of the braking distance. Here's the real formula according to the book : $$ Bd = \frac{V^2}{254 \times f} $$ With : V : the velocity f : the adherence coefficient. But I have on...

I need my formula checked. It involves pregnancy rate, miscarriage rate, stillbirth rate, time breastfeeding, average generation length, multiples, and average number of pregnancies. So let's start off with the conditions: Plenty of food and water for millions Cosmic ray protection...

Homework Statement The problem is attached in uploads Homework Equations The periodic table, all other relevant info given in question The Attempt at a Solution Well, first I would attempt to convert all the products into moles so I can compare the more rations of the products. Firstly, the...

Homework Statement Please look at the photo! Homework Equations -x^2+4x=x^2-6x+5 The Attempt at a Solution I got 2x^2-10x+5 but it says it's wrong

here is a link with the formula: https://portal.uea.ac.uk/documents/6207125/8199714/steps+into+calculus+integration+and+natural+logarithms.pdf i'm talking about the formula that says the integral of f'(x)/f(x)dx = ln(f(x))+C it's kind of hard to put this into Google. where does this formula...

Hello, This algorithm overall is probably more complicated than is correct for the pre-university forum but this question is about a relatively simple aspect of the calculations so I hope that this will be the proper place to ask. I am writing a little program to do some computational geometry...

Homework Statement If ##v## is an integer greater than or equal to ##2##, then ##P_v## is the graph having vertex set ##\{1,2,3, \dots, v \}## and edge set ##\{\{1,2 \}, \{2,3 \}, \{3,4 \}, \dots, \{v-1,v \} \}##. Prove that this graph has ##v-1## edges. Homework EquationsThe Attempt at a...

Let $$\triangle ABC$$ be a right triangle with right angle at $$C$$. Suppose this right triangle has legs $$BC=a$$, $$AC=b$$, hypotenuse $$AB=C$$, and circumradius $$R$$. Two copies of this triangle can be joined to form an isosceles triangle in two ways. With $$a$$ as a common side, you can...

https://en.wikipedia.org/wiki/Euler's_formula (1) eix = cos(x) + isin(x) (2) eixidx = (-sin(x) + icos(x))dx (3) eix = (-sin(x) + icos(x)) / i (4) eix = cos(x) + isin(x) Just lost in circles. Just for fun.. post a solution for x.

Hi, Sorry for this weird question. My computer crashed and also the notes in it. I had a book wherein I'd written all the formulae. There is one formula in notes of Power System. X = cube root of R. I remember there was a website that even had its derivation, but I don't have the bookmarks...