System Definition and 1000 Threads

A mass attached to a spring is oscillating in Simple Harmonic Motion. If an other spring of same sprinc constant is attached parrallel to the other spring, what is the period of this new system (as a function of the initial period). Here's what I did and have no idea if this is right: For the...

I have this word problem, and was wondering how I would go about creating a system of equations. Here is the question: Problem: You are a small forest landowner, and decide you want to sustainably harvest some of timber on your property. There are costs related to the infrastructure needed to...

Homework Statement Why is it that when the total energy of a system less than the max potential energy, it must equal to some potential energy in a potential energy diagram. Homework EquationsThe Attempt at a Solution Total energy intersects multiple points in U(x) diagram. However, since...

If we are talking bout a single atom QM is obviously necessary, but when we are talking about a bunch of molecules (like gases/fluids) statistical mechanics works fine too. I remember it has something to do with ##\hbar## but I don't remember much and I can not quantify it. Thanks

Having a cylindrical iron container with wall thickness of 20 cm, and a total weight of 500 tons when filled with its cargo, how would you be able to calculate its required voltage and current input in a vertical railgun system (relative to the Moon's surface), with an exit acceleration of...

Hey Folks! Just need a quick sanity check ... Putting in a new 4in well and submersible pump ... trying to wrap my brain around the "physics" of it ... Here is what I ***Think I Know*** : 1) The Energy required to move any given volume of water to ground level can be calculated using M*G*H ...

Hello, I'm working on a project to design a system that basically turns off all non essential electrical appliances in the home when it is not occupied. The idea is to reduce energy waste caused by lights, TV's computers etc being left on accidentally. So far I'm thinking that each occupant...

How many things can go wrong simultaneously and apparently independently with a gas central heating system? Mine has been stretching credulity to the limits last weekend. Saturday afternoon, we noticed house getting cold and spotted that pilot light was out. Couldn't get it to relight at all...

Hello. I created a restore point in Windows 8 but it doesn't work because of a problem. "System restore did not completed successfully. Your computer's system files and settings were not changed. Details: System Restore failed to extract the file "C:\Program Files...

Homework Statement A steam heating system is used in winter season, The radiator of a steam heating system has a volume of 25 liters and is filled with superheated water vapor at 200 kPa and 200C. At this moment both the inlet and the exit valves to the radiator are closed. After a while it is...

Homework Statement Homework EquationsThe Attempt at a Solution [/B] the force resultant = (100i +620j +800k) = 379 N moment result is (100i-620j+800k) = 1017 which is not correct! I calculated the moment of all forces about point O using cross product so... (-3i + 2j) x (-200j) + (-3i +2j) x...

Homework Statement Part C ) help Homework Equations So far.. Moment resultant = 1800i +3200k , magnitude = 3070 N*m Force resultant = 500i +300j + 800k , magnitude = 990 N The Attempt at a Solution For the location, I'm not getting x = 1.16, y =2.06. Instead , I am getting Mx = Fr*y --> y...

Homework Statement I have to calculate the partial derivative of an arctan function. I have started to calculate it but I wonder if there is any simpler form, because if the simplest solution is this complex then it would make my further calculation pretty painful... Homework Equations $$\beta...

Homework Statement I am having a issue with the question, when I check the solution to the problem, I can't seem to make sense of how they have derived there equation. Q: By analyzing the superposition of frequencies and amplitudes in the radial velocity data for a star 55 Cancri A, the first...

Homework Statement Homework Equations W=mg F=ma The Attempt at a Solution I'm not sure how I should be answering this problem, and the diagram itself looks odd. I was thinking about how it would work in real life, since the biggest pulley is attached to the leftmost pulley, by the same...

Homework Statement [/B]Homework Equations [/B]The Attempt at a Solution In the second question at 5:32,why doesn't the block have a spring force.In FBD of 2nd block it should have been mg-(T+kx)=ma right?

Homework Statement Two planets are masses stuck to end of long thin rods. These model systems (Rod + mass) will be rotated by a motor at their other end of the rod, as shown in the figure. the length of the rod is proportional to the orbital distance of the planet, and the mass at the end is...

Homework Statement Homework EquationsThe Attempt at a Solution Jacobian of the coordinate- system (## u_1, u_2##) with respect to another coordinate- system (x,y ) is given by J = ## \begin{vmatrix} \frac { \partial {u_1 } } {\partial {x } } & \frac { \partial {u_1 } } {\partial {y} } \\...

Consider, I have a dynamic system model for air compressor. Which means I have modeled the system by including its physics. Does this means I also included the transients of the system? What I think is, when i modeled any system with equations, I think that includes the transients. Is it...

Homework Statement Homework Equations Find out the function of the system. Apply that to input. The Attempt at a Solution From given input output, system is a differentiator. So when input is n u[n] output is differentiating it, we get: n (impulse response) + u[n] Which is not in any of the...

Homework Statement Is the system: y(t) = x(-t) time variant or time invariant? Homework Equations Condition for time invariant: 1) Apply delay to input and check output as Y1 2) Apply input to system without delay and apply delay to output and name it as Y2 If Y1 = Y2, system is Time...

Homework Statement Given a graph (see below) containing the velocities of two stars with respect to the sun, I am asked to calculate the velocity of the centre of mass of a binary system. I am not given the mass of either star, nor the shape of the orbit nor the velocity of the centre of mass...

Homework Statement Homework Equations Using Laplace TF = C (s) / R (s) The Attempt at a Solution Laplacing the equation: 3s C(s) + C(s) = R(s) e-3s So C(s) / R(s) = e-3s / (1 + 3s) Book answer is B I know ramp input is At. Do I laplace it as: A/s2? I'm not sure where I'm wrong

I know that energy increases with distance, but what is the relationship? What are different ways to measure something decreasing over distance or time. I really don't have the time to help my younger sister do her homework so I need someone to help me explain to her the relationship concerning...

I'm aware that the term means the remaining pressure at a point while there is flow. Say the distribution pipes downstream the sprinkler valve have a calculated total head loss of 3 bars during the designed flow. Does that mean that the residual pressure at the sprinkler valve needs to be at...

Homework Statement To find the time period of this simple harmonic motion Homework Equations F= -kx The Attempt at a Solution To check Simple harmonic motion first ,I have to displace the mass by some distance which I take to be x in this case. Therefore the spring will be displaced by a...

Homework Statement Given the following figure and the following variables and parameters, I have been able to come up with the set of differential equation below the image. My question is how does the system of equations 1 which I produced myself differ from the set of equations 2. Below I have...

hi everyone i am working on a project of designing abearing machine i need to calculate the start up toqrue required to my system to move can anyone help?

Can our immune system be partially defective to some small class of pathogens (say flesh eating bacteria) either from birth, due to genetic defect, or latter in life? Our body has a lot of "bad guys" to look out for, maybe it just stops looking for some of the bad guys? Thanks!

Homework Statement It's a solved problem but I don't understand why is there no 30 degree lag from line voltage to lead voltage. Homework Equations Phase voltage = Line Voltage / 1.732 and there is 30 degree lag So shouldn't Ir be at angle 150 degrees.The Attempt at a Solution In Y line and...

Homework Statement Homework Equations V = IR And R becomes 2(r of one conductor) because of return path. The Attempt at a Solution V minimum is at third junction. At VD Using KVL we get: [/B] Drop at AB = (10 + 20 + 50) * 2 * 0.1 = 16 V Drop at BC = (20 + 50) * 2 * 0.08 = 11.2 Drop at CD =...

Homework Statement In a report I am asked to assess the speed of response of various systems, however I am not exactly sure what this means, be great if someone could explain The Attempt at a Solution Step response plots were produced for each simulation and MATLAB was used to assign...

Hi all, I have the system of nonlinear ODEs: $$ \begin{align} \frac{dX}{dt}=&-k_+ A X+k_-Y \\ \frac{dY}{dt}=&\ k_+ A X-k_-Y-\alpha k_+ X Y +\beta Z \\ \frac{dZ}{dt}=&\ \alpha k_+ X Y -\beta Z \end{align} $$ I also have a conservation law that says $D=X+Y+2Z$. Obviously it is not possible to...

As all the z coefficients are the same, it's a good idea to eliminate the z values in the second and third equations, so apply R2 - R1 to R2 and R3 - R1 to R3... $\displaystyle \begin{align*} z &= 12 - x + 4\,y \\ 0 &= -8 + 6\,x - y \\ 0 &= -7 - 11\,x - 9\,y \end{align*}$ Now we can multiply...

The LCM of the $\displaystyle \begin{align*} x \end{align*}$ coefficients is 30, so multiplying the first equation by 6, the second by 10 and the third by 5 gives $\displaystyle \begin{align*} 30\,x - 12\,y + 6\,z &= 18 \\ 30\,x + 10\,y + 30\,z &= 50 \\ 30\,x + 5\,y - 20\,z &= 310...

Would it be possible to transmit information through gravitational waves? It must be a giant leap for mankind if we can utilize gravitational waves for communication since the electromagnetic spectrum for communication is a scarce resource and not much space is left. I imagine that the...

Hi all, I am new on this forum, hope you are doing good. I have a question related to a project I am currently working on. The system is a 40+ floors mix used building, with a cooling system composed of a couple of centrifugal chillers, and a primary/secondary pumping configuration. There is...

$$m_1 \ddot{x} - m_1 g + \frac{k(d-l)}{d}x=0$$ $$m_2 \ddot{y} - m_2 \omega^2 y + \frac{k(d-l)}{d}y=0$$ It is two masses connected by a spring. ##d=\sqrt{x^2 + y^2}## and ##l## is the length of the relaxed spring (a constant). What is the strategy to solve such a system? I tried substituting...

Quantum decoherence means that when a quantum system interacts with its environment, coherence is lost, which means that all the density matrix becomes diagonal after the interaction. I never understood why it is so, but I get a clue here...

Homework Statement Two blocks are attached by strings of negligible mass to a pulley with two radii R1=0.06 m and R2=0.08 m. The strings are wrapped around their respective radios so that the masses can move either up or down. The pulley has a moment of inertia I=0.0023 kgm2 , and is supported...

I am unsure how to choose the boundary conditions for a system of PDEs or for a single PDE for that matter. The situation I am stuck with involves a system of 4 PDEs describing plasma in a cylinder. The dependent variables being used are Vr, Vt, Vz, ni, and the independent variables are Rr...

Consider an underfloor heating system in an apartment building. Each apartment has its own distribution box with a number of loops and a thermostatic mixing valve set to 35°C. The loops are intended to work with a ΔT of 5°C (35-30), and the riser pipe supply temperature is 75°C. Say there are...

Homework Statement The pulleys in the figure (attached) are massless and frictionless, determine the acceleration of eah of m1 and m2, given that m1=4.00 kg, and m2=1.00 kg, and the surface is frictionless and horizontal. Homework Equations For mass m1: T1=m1a1 and mass m2: w2-T2=m2a2 For...

Homework Statement Find the values of k so that each of the following systems in unknowns x, y, and z has (i) a unique solution, (ii) no solution, (iii) an infinite number of solutions. x + y = kz = 1 x + ky + z = 1 kx + y + z = 1 Homework EquationsThe Attempt at a Solution I really don't...

Hi! I want to start solving problems from the text 'Orbital Mechanics for Engineering students' by Curtis 2nd edition. Is this the right place to post? Homework Statement 2.1 Two particles of identical mass m are acted on only by the gravitational force of one upon the other. If the distance d...

We have the linear system of equations $Ax=b$ with \begin{equation*}A=\begin{pmatrix}0 & 1 & 1 \\ 0.5 & 1.0001 & 3 \\ 1 & 2 & 4\end{pmatrix} \ \ \ \text{ und } \ \ \ b=\begin{pmatrix}2 \\ 3 \\ 4\end{pmatrix}\end{equation*} First, I want to calculate the solution using the Gauss algorithm with...

In force-couple system equivalence, We can show that two systems are equivalent if the resultant force in both are equal and that it has the same line of action. So Rx1 = Rx2, Ry1= Ry2, Ma1 = Ma2 Now my book says we can use another form of equation: We can choose 3 point and find the moment...

I have heard it said that in classical physics that if one knows all the particles of a systems momentums and positions, that the evolution of the system can be completely known. I would imagine this also would have to include the nature of all the forces acting on the particle. Also, for...

Hello Guys, I am a mechanical Engineer working on a semester project, to design a waste heat recovery system for a cement plant Air quenching cooler (AQC). For WHR i have to first design a AQC Boiler. According to the Data provided by the plant incharge, Air at the exit of cooler has a volume...

This article suggests that exoplanets are the same size and have equal orbital spacing ,so what is different from our solar system. https://www.sciencedaily.com/releases/2018/01/180109141918.htm An international research team led by Université de Montréal astrophysicist Lauren Weiss has...