Unknowns Definition and 151 Threads

Homework Statement You are given a closed container containing a single atom ideal gas. The volume is V1= 0,45*10^(-3) m^3 Pressure p1 is 3,2 MPa Temperature, T1, is 892 K The volume of the gas is increased to V2= 8*V1 Find the pressure and temperature after the increase of volume...

Homework Statement See attachment. Find the tension in the string that is keeping this weird contraption together. The left stick has mass m, the right stick has mass 2m. m, θ and L are known quantities. Homework Equations The Attempt at a Solution Tried starting with the right...

Hello, I have never really used MATLAB before, and I was assigned some homework on it. While I was able to solve most of them, I was unable to solve this one in particular, even after searching the internet and documentation, there was many kinds that I was left confused. Does anyone know...

I've attached 2 images above. The first is the problem itself and the answer. It's question 9. So, I tried solving this question using the method of finding the inverse of a n x n matrix by augmenting it with the identity matrix of the same dimensions and then applying row ops in an attempt to...

Hello everyone, I have a linear algebra question regarding Cramer's rule. Homework Statement Using Cramer's rule, solve for x' and y' in terms of x and y. \begin{cases} x = x' cos \theta - y' sin \theta\\ y = x' sin \theta + y'cos \theta \end{cases} 2. Homework Equations ##sin^2 \theta...

In general relativity, what are the total number of unknowns for a generic coordinate transform? Is it just 4 * 4 = 16? Is there a way to break those down into combinations of types, such as boosts, rotations, reflections (parity?), etc, or is it just left wide open from an interpretive...

Homework Statement Hello all, I'm trying to solve for 3 unknowns x,y,z. We are given these formulas: http://screencast.com/t/Y8QobUXVB3S3 Homework Equations Please see link provided above. The Attempt at a Solution I first rearrage for root(x) then I rearrange equation 2 for root(y), I...

Homework Statement Find the distance between P and Q P(13x,-23x), Q(6x,6), x>0 *This came from Chapter 1 Linear Functions, Equations, and inequalities Section 1.1 Real Numbers and the Rectangular coordinate System of A Graphical Approach to Precalculus with Limits by Hornsby et alHomework...

Homework Statement The unknowns below read as "m sub 1", "rub sub 2" etc. The maths part of a physics problem states: r1/v1 = r2/v2 Combining these with equation : m1r1 = m2r2 gives: v1/v2 = r1/r2 = m2/m1 Homework Equations The Attempt at a Solution Would anyone be able to explain to me...

Hello, Okay, I have finally worked out a decent curve to work with which is in accordance with my previous post called "How to create a simple mathematical model". According to the attachment in this thread, I have deemed the following equation format as respective to the curve in my...

I am using this in a science fiction novel I am working on for National Novel Writing Month, most of my novel is "soft" but I want to know what we could actually know in this situation. If it helps any the spaceship is about the size of 20 Earths and its going through Saturn.

|1 | |4| |0 | |5| |1| |6 | A|-1 |= |5| ' A |-1|= |3| and A |1|= |8 | |0 | |0| | 1| |5| |1| |11| The first question is, determine the dimensions of A. So I can tell it is a 3x3 Then I'm asked to determine the columns of A, I'm not sure about...

I've always been taught that to solve for 4 unknowns, you need 4 equations. This question seems to suggest that there are in fact solutions. Here's the problem and my work so far. The most I can seem to do is eliminate one variable, I'm not sure how to shake a second one out, let alone all 4.

If I have two independent variables x,y, and two measurements, m1, m2 with errors. And the dependence is thus: m_1 \pm \delta m_1 = f[x,y] m_2 \pm \delta m_2 = g[x,y] Now in my case, f and g are complicated expressions of x and y with no simple solution. (Actually I think i can...

Say I have a system of equations of the following form: a_1 A^2 + b_1 B^2 + c_1 C^2 + d_1 = f_1 a_2 A^2 + b_2 B^2 + c_2 C^2 + d_2 = f_2 a_3 A^2 + b_3 B^2 + c_3 C^2 + d_3 = f_3 Where a,b,c,d,f are coefficients, and A,B and C are unknown variables. 1. Can we write them in terms of two variables...

Help chaps I am having a bad time with this. I can appreciate this is basic, however i can not get my head around it. Im scrubbing up on my maths as i was thinking of doing a HND in Engineering. I am working my way through K.A. Stroud's Engineering Mathematics and simply can't get to grips...

Homework Statement Need Help I have been trying to solve this problem for a while now. I know the quadratic formula has to be used in order to solve this problem but I am having trouble getting started. Question A soccer ball is kicked from the ground level at an angle, such that the wall is...

Homework Statement Two spaceships, each measuring 300 m in its own rest frame, pass by each other traveling in opposite directions. Instruments on board spaceship A determine that the front of spaceship A requires 1 microsecond to traverse the full length of B. What is the relative velocity...

Homework Statement Mass m1, moving to the right, collides with mass m2, which is at rest before the collision. The masses are m1 = 0.1 kg and m2 = 0.2 kg. The scattering angle of m1 will be 30 degrees above the horizontal. a) Calculate the recoil angle phi of m_2. b) Calculate the recoil...

Equation with 3 unknowns. how do i find the maximum solution using matlab?? Hello, Im stuck in matlab, i have an equation with 3 unknowns. how can i get the maximum answer possible? Is there a way with a 3D graph?? Equation: F = ( sqrt((b^2 + c^2) -(2b c cos(y))) x M ) / (b c sin(y))...

Homework Statement Solve 3 equations in three unknowns I, W, and L to find the critical value of L. ***Please See attachment 'differential.gif'**** also note, that I wrote all this using 'mathtype', if its of importance for any to know. Homework Equations Please see attachment...

I have 3 equations with two unknowns of the form: r_i == f_i (g,\beta) Where g and \beta are the independent unknown variables and r_i are known experimentally, but have some error associated with them, say something like 4.3 \pm 0.3 and there are other errors associated with constants inside...

Homework Statement The potential energy of two atoms in a diatomic molecule is approximated by U(r)=a/r^12 - b/r^6, where r is the spacing between the atoms and a and b are positive constants. Find the force F(r) on one atom as a function of r. Make two graphs one of U(r)...

Homework Statement This example comes straight out of the book. Can someone show intermediate steps? Fx = 0: -0.0933Tab - 0.0846Tac + P = 0 Fy = 0: +0.778Tab + 0.705Tac - 1962N = 0 Fz = 0: +0.622Tab - 0.705Tac = 0 Book solution: P = 235 N, Tab = 1401N, Tac = 1236N Homework...

Homework Statement Ok the system we are working with is x-2y =1 x-y+az=2 ay+9z=b Homework Equations 1.)> For which values of a does the system have a unique solution? 2.)> For which pairs of values (a,b) does the system have more than one solution? 3.)>Why is it that the...

Homework Statement I needed to solve this single equation with two unknowns. 199x - 98y = -5 0< x <=99 0< y <=99 I typed the equation into Wolfram Alpha and got an integer solution of: x = 98n + 31 y = 199n +63 when n is an integer Since I know my restriction on x and y I can...

Please help Due in 2 hours. Statics machine equilibrium: reactions- too many unknowns Homework Statement The woman using the lat pulldown machine is holding the 80-lb weight stationary in the position shown. What are the reactions at the built-in support E and pin support F? (A and C are...

Hi, I am working on an investigation for school and, before proceeding (or better, before trying again) I wanted to know if this would work. I have a graph and a proposed model with three variables: A/1 + Be(-Mx) x being time. Is it possible for me to find out these three unknowns...

Homework Statement A projectile is fired at an angle 60 degrees above the horizontal with a speed of 60m/s. A 0.5 second later, another projectile fired at the same speed but at a different angle. The two projectiles collide at some point (x,y). Find the angle the second projectile was fired...

Homework Statement A boat leaves the harbor going 60 degrees north-east with the speed 20km/h. 3 hours later, another boat leaves a harbor 160km to the east with a speed of 70km/h. What course should the second boat have to meet the first? Homework Equations Not 100% sure what equations would...

I'm trying to figure out Ch 4, Sec. 7, Q 25.c of Mathematical Methods in the Physical Sciences, 3rd Ed. It's not homework I'm working on since I'm not in school. Assume that f\left(x, y, z\right) = 0 If x, y and z are each functions of t, show that \left(\frac{\partial y}{\partial...

Hi, I'm wondering what is the quickest/easiest way to solve a system of 3 equations and 3 unknowns that involves squares. Preferably not by hand. Can I use the matrix feature on my TI84, or do I need to use software like Matlab? This set of equations came up while I was trying to solve a...

Homework Statement First of all hi, I was working some mathematics and ended up with 4 unknowns with 4 equations. I tried substituting equations but ended up with squared unknowns. The following is what i ended up with so far. The Attempt at a Solution Any help on how to solve...

I hate it when that happens, but whenever I make 2 equations and 2 unknowns, setting the sum of all torques at the known force (rather than the support) and do sum of all forces equation (either of x or y) I get complete canceling of terms and 0 = 0. What does it mean...

Homework Statement Find I(a) and I(b) for the equaions below: 90 = -j5(I(a)) + j25(I(b)) 60 = (20+j5)(I(a)) - j5(I(b)) Homework Equations Equations in rectangular form The Attempt at a Solution I've tried solving this for one variable and then plugging the answer into the second...

Homework Statement http://img220.imageshack.us/img220/8187/questiong.jpg NOTE: I's are the unknowns, R's and emfs are given Homework Equations The Attempt at a Solution [PLAIN][PLAIN]http://img4.imageshack.us/img4/2180/solutionv.jpg Using Junction, loop rule to come up...

Homework Statement The variables of interest are : Constants are a, b, c, and g Unknowns are x, m, and L The intent is to define x, m, and L in terms of a, b, c, and g. Homework Equations The three dependent equations are : (1) x + g*m = c (2) [x / (a^2)] + L = 0...

How would one go about to solve two equations with two unknows, x and y, where the two equations are of the following form: A/B = c7 where: A = (c1-x)^2 + (c2-y)^2 + (c3-x)^2 + (c4-y)^2 + c5 and B= SQRT{[c6 + (c1-x)^2 + (c2-y)^2 ][c7 + (c3-x)^2 + (c4-y)^2 ]}...

Homework Statement Basically its all on the attached sheet as i don't know how to stick images in the post. im having trouble finding two distances x and y (x+y= 100mm) just need a little help rearranging the equation on the attached word doc. But ‘A’ passes through origin...

Hi all, I am trying to generalize a geometric concept found on page 7 from Steven Weinberg's "Gravitation and Cosmology" from 2 to 3 dimensions. At the end I am stuck with the following set of equations: 1: a1+a2z32+a3z3z4+a4z42=0 2: b1+b2z32+b3z3z5+b4z52=0 3: c1+c2z32+c3z3z6+c4z62=0...

The lower yield point for an iron that has an average grain diameter of 5x10^-2mm is 135 MPa. At a grain diameter of 8x10^-3, the yield point increases to 260 MPa. At what grain diameter will the lower yield point be 205 MPa? Homework Equations Hall-Petch Equation: σy = σo + ky(d^-(1/2)) The...

Homework Statement An ice cube slides on a frictionless sphere. It is placed at the top at of the sphere with radius (R), and given an instantaneous push at speed (S). At what angle(x) from vertical does the ice cube leave the surface of the sphere? Radius = R Speed/Velocity = v angle = x...

Homework Statement I have this equation, but I'm having trouble solving for the unknown :/ I know that d is 109; I just don't know how to get it. see below Homework Equations -dsin35 = -4.9(dcos35/25)^2 The Attempt at a Solution -dsin35 = -4.9d^2 cos^2(35)/25^2 -dsin35 = -4.9d^2 cos(35) x...

Homework Statement This seemingly-innocuous system came up in a quantum mechanics problem: \left. \begin{array}{l} (1 - \sqrt 2 ){C_1} + {C_2} = 0\\ {C_1} - (1 + \sqrt 2 ){C_2} = 0 \end{array} \right] I want to find out what C1 and C2 are. Simple, right? Well... Homework Equations...

Hello, It is known that a system of linear equations is considered overdetermined if there are more equations than unknowns... My question simply stated: is there a term to describe a system of linear equations if there are more equations than unknowns? Google seems to struggle when my...

Homework Statement I have two equations with three unknowns. Obviously, this is indeterminate and not all three variables can be independently solved. However, I only need (want) to solve for two ratios of the three unknowns. I am writing greatly simplified versions of the equations below...

Hello! How do I determine if there is a solution to the following simultaneous equation?: 2a+3b=7 5a+7b=19 9a+5b=32 I have given a specific example but I was interested in the general case. I am confused because I have seen examples with two equations and two unkowns where it has been...

Hello I have a problem regarding matrix equations. In my assigment two products of matrices are given, but none of the factors. [X]'[X] = [A] (2x2) [y]'[X] = [B] (1x2) I know how to solve a matrix equation with one unknown. AX = B and take the inverse etc. But can you give me some...

I know I really need to understand partial diff eqs better for this, but I don't know what subtopic to look for in a pde text. Maxwell eqs are 2 scalar eqs plus 2 vector eqs (3 components) giving eight total equations, coupled in the 6 components of E(x) and B(x). Why not just 6 equations...

A 170g ball is dropped from a height of 2.3m, bounces on a hard floor, and rebounds to a height of 1.8m. The figure shows the impulse received from the floor. What maximum force does the floor exert on the ball...