Column Definition and 317 Threads

Homework Statement Let ##A## be a 2x3 matrix. If Nul(##A##) is a line through the origin in ℝ3, then Col(##A##) = ℝ2. Explain why. Hint: Think about the number of pivots in ##A##. Homework EquationsThe Attempt at a Solution So, Nul(##A##) is the set of all solutions to the equation ##Ax=0##...

Hi, I hope someone can help. I'm wanting to get a better grasp on the connection between the row picture v.s. the column picture of linear systems and their solutions. In the picture below, the row picture are the three graphs on the top and their corresponding column pictures are below them...

This is a hypothetical question: since hydrostatic pressure is calculated as depth of water times its density, would a column of water less than a square foot in cross section still have a pressure at the bottom of depth*density of water? For example, if I had a 1" thick by 1ft wide by 5' tall...

In reading Jules Verne's book A Journey to the Center of the Earth I came to a section where one of the characters questions if the massive weight of the air would be fatal at the center of the Earth. I lack the mathematical skills to derive an equation to graphically represent the results. My...

Homework Statement I need to find the amount of H2 being lost to water by being stored underneath a column of water. About 16 mL of H2 is made and it displaces the column by 16 cm. However the total amount of water is 30 ml/30 cm. I'm not sure which relationship to use to find the pressure of...

Hi, I'm a Civil Engineering student doing my final project for my BE degree. I have developed a software that uses a genetic algorithm for optimizing reinforced concrete columns. I have tested my program with a 17 stories building, and got some very unusual results in the design but much...

A conceptual problem related to a design I'm working on: If I use a pump to suck air out of the top of a vertical pipe, with the bottom of the pipe in water, I can only make the water rise around 10 metres inside the pipe, if I produce a perfect vacuum. Now let's say the pipe was 100m long and...

I am an undergraduate researcher and my university had an SEM donated to us by DOW chemical. It since has been without power and we have to bake the column and the gun chamber. Contacting the company they estimate $17k to send someone out to do it for us. I'm having difficulty finding material...

Hi, In an enclosed system - of say Methane & water - in which the water column is sufficiently large to have significant pressure and some modest temperature difference due to gravity and geothermal effects, how would one calculate / predict the changing methane concentration (or partial...

Hello there. I'm currently trying to come to terms with the aforementioned topics. As I am self studying, a full understanding of these concepts escapes me. There's something I'm not grasping here and I would like to discuss these to clear away the clouds. As I understand it, a basis for some...

Homework Statement Assuming that an OWC device is floating/moored in monochromatic waves. When there isn't air pressure distribution inside (atmospheric condition) the device behaves as an undambed body (with the oscillating chamber open to the atmosphere). When there is air pressure...

Greetings! I am currently making a program which is about lighting columns. And I am currently at a halt because I need some basic physics done before I can complete it. I have a lighting column which is L = 8 m D = 0.087 m M = 69 kg I have a force, applied from the wind load, at F = 1235...

Hello, please see attached text below - this concerns ''rigid column theory''. When a valve is closed, the pressure rises at the valve; the pressure rises above the reservoir pressure by ΔP with a height increase ΔH above H. When the valve is opened, this right hand pressure will disappear and...

Hello Please see attached page from a textbook. Can someone explain why H = 4f.le.vo^2/2d.g and why delta H is given by the expression in the book? Note that the figure it mentions is on the top of the page. I have tried for days here. Thanks

Homework Statement Can someone explain why the M is assigned to be anticlockwise here ? Homework EquationsThe Attempt at a Solution When i assign it as clockwise , i will get -P(δ -v) , which is different from the author ... Can i do so ? Why ?

Hi everyone, I have a cylindrical column under a concentric axial load. The load which is applied in the column is less than the critical buckling force (according to Euler´s formula). Due to this load, the column suffers a displacement (buckling effect), and I would like to determine which is...

Hi, I have a system with a lever arm that's attached to a vertical support at its pivot point. The lever is pushed up by hand and is supported by a stay lid like in the image. I need to calculate the area and thickness of the arm and the column but the only numbers I have is the load attached...

Hello friends, how are you ? Today's question is: How do i choose the data i want to extract from a file in c++ ? I have this data file in columns format, something like: x y z 1 2 3 4 5 6 7 8 9 I know there is the command file.getline() , and this...

Homework Statement In this question, we are interested inthe buckling of column, so we should calculate the moment of inertia (Ixx) or (Iyy) at the column,right? Homework EquationsThe Attempt at a Solution Why the author calculate (Ixx) and (Iyy) using the cross sectional area of beam? is it...

Homework Statement A standing wave with a frequency of 1100 Hz in a column of methane at produces nodes that are 0.200 m apart. What is the value of γ for methane? (The molar mass of methane is 16.0 g/mol)Homework Equations v = sqrt ( γRT/M) where R is 8.341, T = 20 °C and M = 16.0 g/mol. v=fλ...

I find in SQL Server, sys.indexes contains an is_unique column and sys.key_constraints contains unique_index_id. Could you help confirm me that the unique_index_id value in the latter is also the index_id value of the former when its is_unique becomes true or 1 ? Thank you.

Let the matrix $M = \begin{bmatrix}-12&-12&16&-15\\-6&-8&-8&-10\\0&20&0&25\end{bmatrix}$ Find a non zero vector in the column space of $M$ Is it not true that $\begin{bmatrix}-12\\-8\\20\end{bmatrix}$ is a non zero vector in the column space of $M$ ? For some reason it keeps telling me "that...

Hi Physics Forums, I'm wondering if a distillation column is limited by the carnot efficiency and, if so, how this limitation can be used to determine the maximum efficiency of a distillation column with particular hot and cold side temperatures. A distillation column has a hot and cold side...

I would like to ask how to use MATLAB to append new columns into existing excel file without altering the original data in the file? In my case I don't know the original number of columns and rows in the file and it is inefficient to open the files one by one and check in practice. Another...

We are using the following pump to measure the strain on a special tube. http://www.instechlabs.com/Support/manuals/HABP.pdf This special tube is connected on each side to another tube that is connected to one of the two connectors on the pump. (The two connectors of the pump were put parallel...

In the diagram I included, I was curious as to a this situation. The columns of water are all connected and there is a hollow object that is buoyant and it's walls hug up against the walls of the left side of the 2 middle columns so that no water cannot pass between the two walls --- the hollow...

An army of soldiers is marching down a road at 5 mi/hr. A messenger on horseback rides from the front to the rear and returns immediately, the total time taken being 10 minutes. Assuming that the messenger rides at the rate of 10mi/hr, determine the distance from the front to the rear. Can you...

Homework Statement For a concrete column of constant cross sectional area, what is the maximum possible height if the compressible strength is 2.0 x 107 N/m2? The density of concrete is 2.3 x 103 kg/m3. Homework Equations \frac{F}{A} The Attempt at a Solution I am not really sure what I am...

Dear experts, Do you know the buckling load of a column (one end clamped one end free) under axial compressive and transverse lateral forces (applied combined at top free end)? Does the lateral load reduce the critical load or just reduces the stiffness of the column? Would you help me? -Thanks!

I'm reading McCabe and Thiele's classic "Unit Operations of Chemical Engineering" section about the design of sieve-plate columns. Below is a figure showing a column. I have a few questions and some clarification would be great. 1. Isn't the weir for plate n-1 simply the downcomer for plane n...

Hi All, I am doing a query in which I am ALIASING a column name, say 'column name' AS x Can I , at the end of the query ORDER BY x, or must I ORDER BY the given initial 'column name'? (Still having trouble downloading free copy of MSSQL2012, so I cannot test the query). I know this has to see...

Hi All, I am using MySQL in order to design an ERD (Entity Relation Diagram) , and I can make use of indexes, triggers, etc. but for some reason, the columns tab , which allows me to add data or just edit the tables is disabled. I have searched online without success. Any ideas on how to enable...

Part D. I looked up the answer and input it already, which is why it says correct, but i am beyond stumped. No idea how to do this. I know the pressure at the dotted lines are equal and that pressure=force/area. I also know the pressure at an area is equal to whatever is above it so the pressure...

Homework Statement The resonant length of a closed air column at the first resonance is 0.375m, what is the wavelength when at 4th reasonance Homework EquationsThe Attempt at a Solution 1/4λ=0.375m λ=1.5m 1.5m/7 = 0.214m

Homework Statement A column of water 40 cm high supports a 30 cm column of an unknown liquid.What is the density of the liquid? Homework EquationsThe Attempt at a Solution As per the instruction of the teacher I equated their pressures. h1ρ1g=h2ρ2g. And hence arrived at the...

Hi - is there any difference between 'null column vector' and $ |0 \rangle $? Ta

Hello! (Wave) Find the basic feasible solutions of the system of restrictions: $$2x_1+x_2+x_3=10 \\ 3x_1+8x_2+x_4=24 \\ x_2+x_5=2 \\ x_i \geq 0, i=1,2,3,4,5$$ We notice that the rank of the matrix $A=\begin{pmatrix} 2 & 1 & 1 & 0 & 0\\ 3 & 8 & 0 & 1 & 0\\ 0 & 1 & 0 & 0 & 1 \end{pmatrix}$ is...

Homework Statement Hi guys (first post here let me know if I can fix anything that I've done wrong), I'm struggling a little with the second part of this question and seem to be going round in circles A column has the dimensions shown in the diagram below. (a) What is the minimum length of...

Maximum axial load is proportional to the second moment of area. Thus can we reason that aluminium cans are cylindrical because they have a high second moment of area(mr^2) compared to other shapes(Which gives it a higher max axial load.)?

I have just been studying Nullspaces... I want to make the following summary, will it be correct? C(A) is all possible linear combinations of the pivot columns of A. N(A) is all possible linear combinations of the free columns of A (if any exist). edit: I have a feeling these are...

hello, i want to calculate total column water from a radiosonde station data. data are relative humidity, pressure and temperature in various altitude. my course is not physics or meteorology. please help me. is there a free software?

what should I do if I get too small PU making my "AST" (area of steel bars) negative in designing of column?Pls. help thanks a lot.

I am requesting for another set of eyes to double check my work, I believe my answer is correct but I am not sure. I also do not understand why 0.75 is the specific gravity of gasoline in this equation when it actually can range from 0.71-0.77 1. Homework Statement Calculate the pressure...

Homework Statement If I have a column, fixed at both ends, i am aiming to work out the minimum length where buckling is likely to occur. I know this is a similar question to that asked before, however please bear with me. Column outer diameter 100mm, inner diameter 60mm Youngs modulus...

Please help me with these three questions. I'm really struggling to understand these concepts and I think that with an understanding of these three, I will be able to tackle the rest before my test on Wednesday. Thank you. http://www.texpaste.com/n/g4rwmzzw 1) $$ A = \left[\begin{matrix} -6 &...

Is there a relationship between 1 and 2. If so, is it 1 implies 2, 2 implies 1, or if and only if. 1) $\operatorname{null}A=\operatorname{null}B$ 2) $\operatorname{col}\operatorname{rref}A=\operatorname{col}\operatorname{rref }B$

Homework Statement The mass of the weight is 600[kG], the tension in the wire 3000[N]. what is the force of reaction at C Homework Equations Disassembling of forces using pitagoras formula The Attempt at a Solution The vertical reaction at C: $$3000\cdot \sin 53^0+5886=8282$$ In the book 8480

Homework Statement Homework EquationsThe Attempt at a Solution With my solution, I think cold feed means ##q = \infty##, which is seen from my xy diagram. I have some issue understanding the statement "for each mole of feed 0.15 mol of vapor is condensed at the feed plate". I assumed that...

I believe I understand what happens inside an air column that is open at both ends when you cause a disruption such as blowing into it. But I am not sure what happens in the space between the air column and your ear. Please let me explain what my current understanding is and tell me if I'm...

Is the water pressure equal in a sealed column at the top and bottom? If I created 1 bar of pressure would this also be equal at the top and bottom?