Chain Definition and 939 Threads

  1. M

    Simple word problem: Chain rule

    Homework Statement One side of a triangle is increasing at a rate of 3cm/s and a second side is decreasing at a rate of 2cm/s. If the area of the triangle remain constant, at what rate does the angle between the sides change when the first side is 20cm long and the second side is 30cm, and...
  2. J

    What Determines the Velocity of a Falling Chain?

    Homework Statement uploaded Homework Equations rocket equation The Attempt at a Solution i can calculate the force acting on the chain by the ground using rocket equation but i cannot show that the velocity is that.
  3. M

    Prove the equality : Multivariable chain rule problem

    Homework Statement Prove that (\frac{\partial u}{\partial x})^{2} + (\frac{\partial u}{\partial t})^{2} = e^{-2s}[(\frac{\partial u}{\partial s})^{2} + (\frac{\partial u}{\partial t})^{2}].Homework Equations u = f(x,y) x = e^{s}cost y = e^{s}sint The Attempt at a Solution I started out by...
  4. pellman

    Chain rule for functions of operators?

    This is strictly a math question but I figured that since it is something which would show up in QM, the quantum folks might be already familiar with it. Suppose we have an operator valued function A(x) of a real parameter x and another function f, both of which have well defined derivatives...
  5. R

    Apparently easy Chain Rule Problem

    Homework Statement F(s) = ( s - \frac{1}{s^2})3 I have to calculate the derivative of this using chain rule everytime i try i get something way different than in the back of the book... my first move is 3( s - \frac{1}{s^2})2 X ( 1 + \frac{2}{s^3}) is this correct? then expand...
  6. S

    Equation of motion for a chain sliding down an edge

    I studied physics a long time ago and somebody just asked me this question. After trying for a while I couldn't work it out. The situation is this: there's a chain of length $l$ on a table, of which a portion, of length $x_0$, is hanging out (enough so that when you stop holding it down, the...
  7. M

    Chain of mass M with length L (SPhO 2009)

    Homework Statement A chain of mass M and length L is suspended vertically with its lower end touching a scale. The chain is released and falls onto the scale. What is the reading of the scale when a length of the chain x has fallen? You may neglect the size of the individual links. [10]...
  8. L

    Multivariable calculus. The chain rule.

    Homework Statement Let x=x^2ysin(u)tan(v), where x(u,v) and y(u,v) are smooth functions that, when evaluated at u=1 and v=-3 satisfy x=2.112, y=4.797, \partialx/\partialu = -3.491, \partialx/\partialv = -2.230 , \partialy/\partialu = 1.787 , \partialy/\partialv = 1.554. Then the...
  9. Y

    What Am I Missing in the Chain Rule Calculation?

    \hbox { Let }\; u(x,y)=v(x^2-y^2,2xy) \;\hbox { and let }\; t=x^2-y^2,\;s=2xy u_x = 2xv_t \;+\; 2yv_s u_{xx} = 2v_t + 4x^2 v_{tt} + 8xyv_{ts} + 4y^2 v_{ss} The u_{yy} can be done the same way and is not shown here. According to Chain Rule: u_x = \frac{\partial v}{\partial x}...
  10. M

    Learning Calculus: Chain Rule and Derivatives

    I am currently learning calculus and just had my lecture on the chain rule. I noticed that we haven't learned how to take the derivative of a function like 2^2+x or 3^4+x. Any example works.. Is this something I will learn later as I progress through calculus or what?
  11. Telemachus

    Composition and the chain rule

    Homework Statement I have a problem with the next exercise: Given de function f(x,y)=\begin{Bmatrix} \displaystyle\frac{xy^2}{x^2+y^2} & \mbox{ if }& (x,y)\neq{(0,0)}\\0 & \mbox{if}& (x,y)=(0,0)\end{matrix} with \vec{g}(t)=\begin{Bmatrix} x=at \\y=bt \end{matrix},t\in{\mathbb{R}} a) Find...
  12. T

    How Does the Falling Chain Problem Illustrate Variable Mass Dynamics?

    Homework Statement This is from Serway's book Prob 9.71...(busying preparing for GRE) A chain of length L and total mass M is released from rest with its lower end just touching the top of a table, as in figure (a). Find the force exerted by the table on the chain after the chain has...
  13. A

    Solving G(y) with the Chain Rule: Where Do I Start?

    I need some help with the chain rule...Thank you for helping me:) Question: G(y)=((x-1)^4)/(((x^2)+2*x))^7 I have no idea where to start.
  14. S

    Designing Chain Lifting Device for 400 Metric Tonnes

    I'm looking for some input on the design of a lifting device. The design is required to accurately lower lower a load of 400 metric tonnes through a height of 50m, return to the top of it's travel and lower the next load and so on. I'm currently thinking along the lines of a two-pronged tower...
  15. S

    How to Obtain the Transition Probability Matrix in a Birth Death Markov Chain?

    Hi I am trying to model the behaviour of 2 independent ON-OFF sources. My state diagram is as follows state 0 = both sources are OFF state 1 = 1 of the sources are ON state 2 = both sources are ON The transition rates are given as BIRTH RATE = lamda(i) = (N-I)*lamda DEATH RATE =...
  16. B

    Chain rule with second derivative

    Homework Statement I trying to find the second derivative of xe^x Homework Equations chain rule The Attempt at a Solution Two find the first derivative I use the chain rule. f'(y)g(y)+f(y)g'(y) so I get e^x+xe^x is the second derivative e^x+f'(y)g(y)+f(y)g'(y)...
  17. M

    Chain with distance-dependent mass problem

    1. A particle of mass m is tied on one end of a very long chain which has a linear density μ (kg/m) and lies on a surface with the chain wound next to it. The particle is thrown upwards with an initial velocity V. Find the maximum height the particle is going to reach. My question is not what...
  18. R

    Understanding Tension in Chain Slings: A Statics Problem

    [PLAIN]http://img245.imageshack.us/img245/7903/staticsproblem.jpg I don't know where to start with this because I'm unsure as to how the force is distributed in the chain.
  19. C

    Derivation of Decay Chain Formulae

    I'm afraid I'm suffering from a bit of brain block in try to get from the simple statement of change in the number of daughter nuclei arising from the decay of parent nuclei. The basic statement is straight forward... \frac {dN_d}{dt} = \lambda_pN_p - \lambda_dN_d Subscripts d and p denote...
  20. S

    Chain rule with leibniz notation

    Homework Statement If y=f((x2+9)0.5) and f'(5)=-2, find dy/dx when x=4 Homework Equations chain rule: dy/dx=(dy/du)(du/dx) The Attempt at a Solution In my opinion giving f'(5)=-2 is unnecessary as: y=f(u)=u, u=(x2+9)0.5 dy/dx= (dy/du)(du/dx) (dy/du)= 1 (du/dx)= x/((x2+9))0.5 dy/dx =...
  21. jegues

    How does the chain rule apply to partial derivatives?

    Homework Statement See figure. Homework Equations The Attempt at a Solution Here's what I got, \frac{ \partial z}{\partial x} = \left( \frac{\partial z}{\partial u} \cdot \frac{\partial u}{\partial x} \right) + \left( \frac{\partial z}{\partial v} \cdot \frac{\partial...
  22. D

    What is the Chain Rule for Differentiating tan^3(x) + tan(x^3)?

    Homework Statement tan^3(x) + tan(x^3) Homework Equations The Attempt at a Solution tan^3(x) + sec^2(x^3) + 3x^2 Im not sure how to do the tan^3(x) and not even sure I did the tan(x^3) right
  23. D

    Chain Rule: Solving y' for y=cot^7(x^5)

    Homework Statement y=cot^7(x^5) Homework Equations f(x)=f(g(x)) The Attempt at a Solution u=(x^5) y'=7(-csc^2)^6(x^5) * 5x^4
  24. K

    Is the Multivariate Chain Rule Being Applied Correctly?

    Homework Statement Find \frac{\partial z}{\partial y} [/itex] where z=F(u,v,y), u=f(v,x), v=g(x,y). The Attempt at a Solution If I remember multivariate calculus at all, this should be (please forgive the abuse of notation) \frac{\partial z}{\partial y} = \frac{\partial z}{\partial...
  25. C

    How do I calculate the individual interactions between two links of a chain?

    I want to simulate the (probably chaotic) two dimensional movement of a chain, given that there is no gravity, and all of the links of the chain have some constant mass. Additionally, there is an assumption that the chain cannot collapse - all of the links of the chain will always be touching at...
  26. J

    Is my U-238 Decay Chain Program Accurate After 4.468 Billion Years?

    I wrote a program to find the percent of each element in the decay chain for U238 after a certain amount of time. I used the Bateman equations for serial decay chain below: N_n(t)= \frac{N_1(t)}{\lambda_n } \sum_{i=0}^n \lambda_i \alpha_i \exp({-\lambda_i t}) \alpha_i=\prod_{\substack{j=1 \\...
  27. W

    Can Sustained Nuclear Chain Reactions Achieve Constant Acceleration in Space?

    Is it possible to make an object travel with a constant acceleration using sustained nuclear chain reaction in space?
  28. M

    Flip dx/dy according to chain rule

    Hi I've just been reading something which is essentially how to work out what the deriviative of y=b^x is. Basically the explanation gets to the point which I understand and says \frac{dx}{dy} = \frac{1}{yln(b)} It then says because of the chain rule you can simply flip this to get...
  29. C

    Solving for f'(x) using the chain and quotient rules

    Homework Statement Let f(x) = (x2)/sin(x)2. Find f'(x). Homework Equations Chain rule, quotient rule The Attempt at a Solution f'(x) = [2xsin(x)2 - x22cos(x)2]/(sin(x)2)2
  30. G

    Is This 2 Year Old Really a Chain Smoker?

    http://www.youtube.com/watch?v=xePgC8wHDXI&playnext_from=TL&videos=7LWJAQz6KJ8 Maybe the world really is going to end in 2012 with people running around raising their kids like that.
  31. C

    Partial derivatives and chain rule

    Homework Statement express (\frac{\partial u}{\partial s})_{v} in terms of partial derivatives of u(s,t) and t(s,v) Homework Equations The Attempt at a Solution I'm pretty stuck with this problem. I know that dv = (\frac{\partial v}{\partial s})_{t} ds + (\frac{\partial...
  32. C

    Derivative Question- Chain Rule

    Homework Statement The derivative of the function h(x) = sin((x2 + 1)2)Homework Equations Chain Rule The Attempt at a Solution h(x) = sin((x2 + 1)2) f(u) = sinu^2, f'(u)= 2ucosu^2 g(x) = x^2+1 g(x)= 2xI get lost putting this back together but: 2(sinu^2)[cos(sinu^2)^2](2x) ?
  33. D

    Finding work for lifting a chain with winch on top of a building

    Homework Statement A winch is positioned on top of a building, a distance 70 m above ground level. A chain of length 95 m and a mass per unit length of 1.2 kg/m hangs from the winch along the side of the building. Find the work done (in Joules) in reeling up 60 m of the chain.Homework...
  34. P

    Finding resistance of (semi-)infinite resistor chain between two points.

    Homework Statement What is the resistance of the (semi-)infinite resistor chain below, between points A and B, if R = 25 ohms? The Attempt at a Solution I am not sure where to begin exactly, but I am thinking of this formula: VAB=VB-VA=∑ε-∑i.R or...
  35. X

    Chain Rule Examples: Find dz/dt and dz/dv with Substitutions

    chain rule someone help please 1. let z=y^2-x^2cosy; x=t^3 y=cost, find dz/dt 2. let z=(x-y)^3;x=u+2v,y=2u-v,find dz/dvmy attempt: so i know the chain rule is (dz/dx)dx+(dz/dy)dy 1. should i substitute the x and y into t first or should i do the partial derivative first? 2. same thing what...
  36. G

    Multivariable Calculus: Applications of Grad (and the Chain Rule?)

    Homework Statement We say that a differentiable function f : \mathbb{R}^n \rightarrow \mathbb{R} is homogenous of degree p if, for every \mathbf{x} \in \mathbb{R}^n and every a>0, f(a\mathbf{x}) = a^pf(\mathbf{x}). Show that, if f is homogenous, then \mathbf{x} \cdot \nabla f(\mathbf{x}) = p...
  37. M

    Chain with 2 links lifted vertically - Force

    Homework Statement A chain consisting of two links, each of mass 0.5 kg, is lifted vertically with an acceleration of 3.0 m/s2 upward. The magnitude of the downward force exerted on the top link by the bottom link is? Homework Equations F = ma The Attempt at a Solution 1 is...
  38. R

    Multivariable chain rule (with implicit variable)

    Homework Statement If T is implicitly defined via the relationship f(x, y, z, T) = 0 to be a differentiable function of x, y and z, show that the first partial derivative of T with respect to z can be found using: \frac{\partial T}{\partial z} = -\frac{\partial f}{\partial z} / \frac{\partial...
  39. N

    Chain rule and partial derivatives

    Homework Statement Suppose the differentiable function f(x,y,z) has the partial derivatives fx(1,0,1) = 4, fy(1,0,1) = 1 and fz(1,0,1) = 0. Find g'(0) if g(t) = f(t2 + 1, t2-t, t+1).Homework Equations The Attempt at a Solution Ok I'm given the solution for this and I'm trying to work through it...
  40. L

    Mass of chain in shape of parabola

    Homework Statement A chain in the shape of y = x^{2} between x = -1 and x = 1, has density of |x|. Find M, and CM. Homework Equations The Attempt at a Solution \int^{1}_{-1}|x|dx = \int^{0}_{-1}-xdx + \int^{1}_{0}xdx = 1 I got this far and realized that I did nothing with...
  41. Y

    Falling chain center of mass dynamics

    Not sure if this is in the right subforum but: A chain of uniform mass density, length b, and mass M hangs in a loop from the ceiling (both its ends are adjacent to each other) At time t = 0, one end, end B is released. Find the tension in the chain at point A after end B has fallen a distance...
  42. H

    Chain rule for partial derivatives

    If I have u = u(x,y) and let (r, t) be polar coordinates, then expressing u_x and u_y in terms of u_r and u_t could be done with a system of linear equations in u_x and u_y? I get: u_r = u_x * x_r + u_y * y_r u_t = u_x * x_t + u_y * y_t is this the right direction? Because by...
  43. J

    Chain Rule for V=(1/2)*sqrt((v*V)/x)(n*df/dn-f) - Solving for V

    Homework Statement n=y*sqrt((V)/(v*x) and Q=sqrt(v*V*x)*f(n) so i have V=-dQ/dx=(dQ/dn)*(dn/dx) and the final answer is V=(1/2)*sqrt((v*V)/x)(n*df/dn-f) Homework Equations The Attempt at a Solution i have tried diff. by hand and also by maple and cannot get the answer. What am i...
  44. C

    How Do I Apply the Chain Rule for Second Order Partial Derivatives?

    I have a function F(u,v) that I need to get first and second order partial derivatives for (Gradient and Hessian). F(u,v) is very ugly, so I'm thinking of it like F(x,y,z) where I have another function [x,y,z]=G(u,v). So, I got my first orders, e.g.: dF/du = dF/dx*dx/du + dF/dy*dy/du +...
  45. E

    Solving Markov Chain Problem for Water Distribution Co. in California

    A water distribution company in southern California gets its water supply from the north and sell it back to its customers in Orange county. Assume the following simplified scheme: 3 MG (millions of gallons) of water arrives from the north at the beginning of the month. The company can store up...
  46. S

    Need some help with a derivative and the chain rule

    Okay so I'm doing chain rule work to go over the stuff from calc 1 before I take a departmental exam and I've run into this problem: Homework Statement Take the derivative of: f(x) = \frac{sin(x^2)}{ln sinx} Homework Equations Here's the formula I used (and always do) for the...
  47. H

    What is the tension in a hanging chain problem?

    Homework Statement A 20 m length of chain weighing 2.0 N/m is hung vertically from one end on a hook. Answer in Newtons 1.What is the tension three quarters of the way up? 2.What is the tension 1 m from the top? 3.What is the tension 1 m from the bottom? Homework Equations F...
  48. K

    Calculus 3: Finding Current Rate of Change in Electric Circuits Using Chain Rule

    In a simple electric circuit, Ohm's law states that V = IR, where V is the voltage in volts, I is the current in amperes, and R is the resistance in ohms. Assume that, as the battery wears out, the voltage decreases at 0.03 volts per second and, as the resistor heats up, the resistance is...
  49. J

    Markov Chain - Find the Stationary Distribution

    Ok, I had a homework problem that I cannot for the life of me, figure out. I've tried to google for different sources that would show me how to find the stationary distribution of a markov chain, but I can't seem to find one that makes sense to me. The transition matrix of a markov chain is...
  50. M

    Use the chain rule to find the derivative

    Homework Statement f(x) = ((x^2+2)^2)/(x+2)^1/2 Use the chain rule to find the derivative Homework Equations None The Attempt at a Solution ((x^2+2)^2)(x+2)^-1/2 PS: Answer in the book is 3x((x^2+2)^1/2) I have no idea how they get it there, would like some help, thx!
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