Chain Definition and 939 Threads

I found this to be very interesting - as someone who never really paid attention to biology. I have heard of PCR testing during the CoVid days, but I didn't know what "polymerase" is, or what "chain reaction" had to do with the test.

Part (a) is fine. I have attached my work for this here anyway because I use the first two lines of (a) in my proof of (b). In part (b), I get the extra factor of ##\frac{1}{r} \frac{\partial z}{\partial r}## and I don't know why. Can anyone help? I am unable to figure out the flaw in my steps :(

Source: Paul's Notes (https://tutorial.math.lamar.edu/Solutions/CalcIII/ChainRule/Prob6.aspx) In his solutions: where he computes the stuff in red. My question is, why is $$\frac{\partial y}{\partial p}$$not $$1+3\frac{\partial t}{\partial p}=1+3\left(\frac{-1}{2}\right)=\frac{-1}{2}$$ Thanks

I wrote this a while back Forums Engineering Mechanical Engineering Mechanical design - cam timing chain versus gear-driven (1 Viewer) Thread starterpnorm91 Start date Sep 12, 2013 Sep 12, 2013 I have since found some new updates. Back in the early 1990s when the SB2 small block chevy...

Professor says one way to do this is to convert the equations to Itô form and back. ##dX_t=bdt+\sigma\circ dW_t## converted to Itô's SDE is \begin{align*} dX_t=&\left(b+\frac{1}{2}\sigma\frac{\partial}{\partial x}\sigma \right)dt+\sigma dW_t. \end{align*} We use Itô's formula to compute...

On an engine, the timing chain has colored links, and you have to line up these colored links on timing marks on the engine. There's typically marks on sprockets, bearing caps, gears. A understand that you have to line these up in order to get proper timing. I understand that is the reason why...

This is probably a stupid question, but I have never realised that there's an order things should be done in the chain rule , so for example ## \nabla(\bf{v}.\bf{v})=2\bf{v} (\nabla\cdot \bf{v}) ## and not ## 2 \bf{v} \cdot \nabla \bf{v} ## Is there an obvious way to see / think of this...

I want to follow the Lienard-Wiechert potential derivation in Robert Wald's E-M book, page 179. I do not understand $$dX(t_\text{ret})/dt$$ on the right side. I assume the chain rule is applied, but I can't see how. $$ \frac{\partial[x'^i - X^i(t - |\mathbf x - \mathbf x'|/c)]}{\partial x'^j} =...

I am currently self-studying Taylor and Mann's Advanced Calculus (3rd edition, specifically). I stumbled across their guidelines for a proof of the chain rule, leaving the rest of the proof up to the reader to complete. I was wondering if someone could look over my proof, and point out any...

I have been given an electrical chain hoist to repair. The symptom is that it suddenly stopped working. I have checked the motor's windings and they each show similar DC resistance of 0.0018 ohms. I have attached the schematic (dunno why it was rotated 90 degrees during the upload). The hoist...

Hi. I have next task: Three current sources with EMF E1 = 11 V, E2 = 4 V and E3 = 6 V and three resistors with resistance R1 = 5 Ohms, R2 = 10 Ohms and R3 = 2 Ohms are connected, as shown on picture below. Determine the current strengths I in the resistors. Internal resistance sources neglect...

So the chain rule for second derivatives is $$ \frac {d^2 y} {d t^2} = \frac{d}{dx}(\frac {dy} {dx}) \cdot \frac {dx} {dt} \cdot \frac {dx} {dt} + \frac {dy} {dx} \cdot \frac {d^2 x} {d t^2} = \frac{d^2 y}{d x^2} \cdot (\frac {dx} {dt})^2 + \frac {dy} {dx} \cdot \frac {d^2 x} {d t^2}$$ Today I...

[Mentor Note -- postprocessed attached image for clarity] Hello! Looking for a formula(s) on how I can determine the Torque and RPM needed on the chain (by hydraulic motor) to move the load in the illustration at 240 inches per minute. The load will vary, so I won’t ever really need to push...

b)Suppose that the coin flipped on Monday comes up heads. What is the probability that the coin flipped on Friday of the same week also comes up heads? My attempt to answer this question:

I'm having some problems using the chain rule and I'm not sure where the trouble lies. For example: If I'm not mistaken, if we have the composite function f(g(n)) then \Delta f(g(n)) = \dfrac{ \Delta f(g) }{ \Delta g } \dfrac{ \Delta g(n) }{ \Delta n } Let f(g(n)) = (n^2)^2. Then f(g) = g^2...

In order to be able to solve the problem, I think I must find the equation of ##h## with respect to ##\dot h##. Assuming that ##F## is the action-reaction force between the stone and the end of chain, then the Newton's equation For the stone:$$-F-mg=m \ddot h$$ $$-\int (F+mg)dh = \frac 1 2...

I originally thought you’d have to use the chain rule to get h’, as in: f’(g(x))*g’(x). Plugging in 1 for x, I got an answer of 10. An online solution, however, said that you only had to get f(g(1)), which was f(-1), then look up f’(-1) in the table. Both approaches seem logical to me, but they...

In Chapter 3 of Thomas’s Calculus, they give the following proof of the Chain Rule. After the proof, the text says that this proof doesn’t apply when the function g(x) oscillates rapidly near the origin and therefore leads delta u to be 0 even when delta x is not equal to 0. Doesn’t this proof...

The following problem is seriously tricky and I urgently need help with it, thanks. For part a: we have the following transition probability matrix P = a0 a1 a2 a3 a0 a1 a2 a3 0 a0 a1 b2 0 0 a0 b1 Now, is a0 = a1 = a2 = a3 =...

Consider a Markov chain with state space {1, 2, 3, 4} and transition matrix P given below: Now, I have already figured out the solutions for parts a,b and c. However, I don't know how to go about solving part d? I mean the question says we can't use higher powers of matrices to justify our...

The force is -Mg and distance is L/3. So W=-MgL/3. Not right! Maybe it’s done using COM but there is no additional information is given.

The problem states to find the work per particle to assemble the following NaCl chain. I just want to post my work here to verify I have the correct answer. My work is attached in the image provided.

In his solution, Morin solves the problem as the hint suggests: cutting the chain into small pieces, taking the component of the external forces along the curve (which is just the component of gravity here) and summing up an in integral, obtaining 0. He then claims that because the "total...

The force exerted downwards on the scale by the chain when it is kept on it would be Fg= Mg =λLg where λ is the linear mass density However when the chain is dropped onto the scale it exerts an additional force due to its change in momentum The force exerted by each part of the chain would...

In the book, it is stated that if your hand move a distance x, then x/2 is the length of the moving part of the chain because the chain gets “doubled up.” as in the image below. I don't get the meaning of this. For example, if our hand move L metres from initial position, shouldn't the moving...

Given events ##X_i## and the following: ##P(X_3|X_1,X_2)=P(X_3|X_2)## and ##P(X_4|X_1,X_2,X_3)=P(X_4|X_3)## prove ##P(X_4|X_1,X_2)=P(X_4|X_2)##? Special case proof: Finite number of possibilities for each ##X_i##. Transition matrix from ##X_2## to ##X_4## is product of transitions from...

[Mentor Note -- thread moved to the schoolwork forums from the technical forums] Summary:: I would like to understand how to calculate the error of a measurement provided by a measuring chain Hello to everyone, I'm going to explain the problem I would like to understand better. Thank you for...

##f_x=3*x^2+y## ##f_y=2*y+x## ##(3*(t^2)^2+e^{t-1})*2*t+(2*e^{t-1}+t^2)*e^{t-1}## Well, I am not sure how to evaluate it. I got a wrong result by multiplying by 0.1, i.e. ##((3*(t^2)^2+e^{t-1})*2*t+(2*e^{t-1}+t^2)*e^{t-1})*0.1## I guess it is trivial but I am lost. :(

Just a nice experiment; comment in Russian is obvious

Hi, I am interested in the topic of hand calculations of chain link's strength. I am talking about a regular industrial chain with hanging weight. From what I've read, there are 3 potentially possible approaches: - Lame's problem (circular cross-section has to be replaced with equivalent...

Firstly, There is something I want to clarify. When the system starts moving, parts of the chain that still lies on the table, which have mass ## \frac {(L- y_0)M} {L}##, will be pulled by the force that the hanging chain's weight exert,right? If yes, then : As far as I know, the formula ##F=...

But, If I use chain rule than, I get that. ##\vec v_i = \frac{dr_i}{dt}=\sum_k \frac{\partial r_i}{\partial q_k} \cdot \frac{\partial q_k}{\partial t}## But, they found that?

This is the solution from my textbook, and I have some questions about the method The mass of hanging chain : $$m_h =\frac m 5$$ the center of mass of the hanging chain : $$h_1 = - \frac{1} {2} \cdot \frac L 5 = - \frac L {10}$$ (the minus sign here means that it is under the table surface)...

Hi, PF ##y^2=x## is not a function, but it is possible to obtain the slope at any point ##(x,y)## of the equation without previously clearing ##y^2##. It's enough to differentiate respect to ##x## the two members, treat ##y## like a ##x## differentiable function and make use of the Chain Rule...

T(y)-T(y+dy)=ug(dy) is what I have got. How would I solve this? Or is there a simpler method.

Today I learned that U 235 is not a German Uboat

So first thing I tried was to separate the variables then differentiate by parts, setting u = E and v = 1/ln(E) (and the other way around) but I couldn't do the integral it gave. Then I tried to reason that because dx was constants then dE/dx is equal to E/x but I was told that's not the case...

One dimensional Ising model is often treated as open chain system with free ends. Then when external field is added it is treated with cyclic boundary condition. Can someone explain me are those methods equivalent, or not?

First I quote the text, and then the attempts to solve the doubts: "Proof of the Chain Rule Be ##f## a differentiable function at the point ##u=g(x)##, with ##g## a differentiable function at ##x##. Be the function ##E(k)## described this way: $$E(0)=0$$...

My attempt: At first, only a small part of the chain has fallen through. Let that part have mass m, speed v, and length x. Suppose the chain has a mass per unit length of u. To accelerate a small length of chain on the table to speed v, Force needed = v dm/dt = v (dm/dx) * (dx/dt) = uv^2...

I have seen the solution for this problem but still there are some things I do not understand and would like clarification. In the equations below I understand that we use the chain rule on m and v but what I don't understand why m*dv/dt is 0, I don't think is because the acceleration of dm is...

Hey everyone, could anyone help me figure out how to use chain rule to solve these questions in the attachments below?

I have no answer or solution to this. So I'm trying to seek a confirmation of whether this is correct or not: ##df = \frac{\partial f}{\partial x}dx + \frac{\partial f}{\partial t}dt ## ##\frac{df}{dt} = \frac{\partial f}{\partial x} \dot x + \frac{\partial f}{\partial t} ## Therefore, ##...

I want to take the derivative of a composite function that looks like $$f( g(x), h(x) ).$$ I know from Wolfram that the answer is $$\frac{ df( g(x), h(x) ) }{ dx } = \frac{ dg(x) }{ dx }\frac{ df( g(x), h(x) ) }{ dg(x) } + \frac{ dh(x) }{ dx }\frac{ df( g(x), h(x) ) }{ dh(x) }.$$ We can...

In the figure assume the "ceiling" moves with motion ##Y(t)##, i.e. it is a point support. Applying Newton's law in the vertical direction ##T(y).\hat{y}=\rho y[g+\frac{d^{2}Y}{dt^{2}}]## If ##\theta## is the angle between ##T## and ##\hat{y}## that means ##|T|\cos\theta=\rho...

Hello! Now this is not really a physics problem of the usual kind but I'd say you could consider it one.Still I'd like to post my problem here because here I always get great help and advice.Now for this problem in particular,it is in the section of the book that deals with derivatives so I...

Hi, I'm not sure how to approach the design calculations for chain conveyor. It's rather easy to find formulas for belt conveyor but it's not the same. I also thought about the use of procedure applicable to chain drive but in case of conveyor load is placed directly on the chain (or a pair of...

I don't need the whole answer just a few tips to do it. I think it's something with the two different radiuses, but I'm really bad at this. We did a similar one in class, but there is a trick in this one that I can't figure out.

Hello, I hope the equation formatting comes out right but I'll correct it if not. So far, I have attempted to write ##\ddot{a}_k(t) = \sum_{n}(u^{k}_n)^*\ddot{q}_n(t) ##. Then I expand the right hand side with the original equation of motion, and I rewrite each coordinate according to its own...