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1. ### Engineering Thevenin Equivalent Circuit

Would the first step be setting all those current sources to 0? Thus left with the remaining voltage source and the two resistors? http://img820.imageshack.us/img820/2318/q2z4.png [Broken]
2. ### Engineering Thevenin Equivalent Circuit

Homework Statement Above given is the circuit I am supposed to simplify where the 1/5Ω resistor is the load. I'm unsure how to convert this circuit into an equivalent Thevenin Circuit. Homework Equations V = I*R (Ohm's Law) The Attempt at a Solution Using Microcap and it's...
3. ### Laplace Transforms

Thanks, that was a mistake sorry So basically use the integration rule and integrate te^t and then apply the Heaviside function? I'm sorry, I'm not too confident with the Integral method, but.. integral{te^t} = (t-1)e^(t-st) I'm not sure how to work from there. [Googling Heaviside...
4. ### Laplace Transforms

Homework Statement Laplace transform: te^t*H(t-1) Homework Equations L{te^t} = 1/(s-1)^2 L{H(t-1)} = e-s/s The Attempt at a Solution Using e^(at)f(t) -> F(s-a) with..e^(1t)H(t-1) We can get, e^(-1s-1)/(s-1) = e^(-s-1)/(s-1) [I think?] Thus applying tf(t) -> -dF/ds Derive[e^(-s-1)/(s-1)]...
5. ### Process Engineering - Multiple Evaporators

Homework Statement Here's a quick sketch of the problem: http://prntscr.com/15ltr5 Essentially, Sugar Solution enters the first evaporator at 65°C and the water is boiled (to 100°C) so that a sugar concentrate comes out (bottom of evaporator) and saturated steam leaves the evaporator...
6. ### Chemistry Chemical Process Analysis - Mole Flow Rate

Homework Statement 120 mol/min of Propane (C3H8) is burned in the presence of air (21% O2 and 79% N2) in a furnace, two reactions occur: Complete Combustion: 67%, propane is burned to CO2 and H2O Incomplete Combustion: 18%, propane is burned to CO and H2O Oxygen is supplied at 70%...
7. ### Electron Configurations Phosphorus

Basically, this 1s3 2s3 2p6 3s2 3p1 violates Pauli's Law because of the third electron in the 2s orbital.
8. ### Electron Configurations Phosphorus

Pauli's Exclusion Principle... each electron in an atom has a unique set of quantum numbers which must abide to a specific criteria... where basically, any orbital can only contain a maximum of two electrons. Ahh, when I actually bother to read my notes, I see that p-orbitals have 3...
9. ### Electron Configurations Phosphorus

Homework Statement Here are the following Electron Configurations of Phospohorus 1. 1s2 2s2 2p6 3s1 3p4 2. 1s3 2s3 2p6 3s2 3p1 3. 1s2 2s2 2p6 3s2 3p2 3d1 4. 1s2 2s2 2p6 3s2 2d1 3p2 5. 1s2 1p6 2s2 2p5 6. 1s2 2s2 2p6 3s2 3p3 Questions: Which of these have non-existent orbitals...
10. ### Heaviside and Laplace Transforms

Fair enough then, I have a Chemistry Prac in a bit so I don't have much time to calculate it, but, would the end result come out to as what I have gotten? Or is there a mistake that needs to be corrected here? Thanks, I appreciate the feedback.
11. ### Heaviside and Laplace Transforms

This was my first homework question, I assumed it was correct since the tutorer looked at it and ticked me off, but, this is the question where I dragged my error from... Attempt #2 (t²-1)H(t-2) + (0-t²)H(t-3) (t²-1) = (t-2)²+4(t-2)+4-1 H(t-2) [(t-2)²+4(t-2)+3]...
12. ### Heaviside and Laplace Transforms

Aha, that's not a problem at all, I'm assuming a lot of what you've just mentioned is something I'll be coming across in my course :)
13. ### Heaviside and Laplace Transforms

Thanks BruceW, unfortunately, I did not know that, going through my lecture notes and slides, there's no information on double checking our Laplace Transforms. Thanks a lot for telling me this, I'll Google it later to do a little bit more research on it! And Ray Vickson, much appreciated, I...
14. ### Heaviside and Laplace Transforms

Ah, it's a mistake carried over from a previous homework question I've done. How would you go about substituting in values of 't' in order for it to validate my f(t) value? For example... cos(2∏(t-3))H(t-3) - cos(2∏(t-6))H(t-6) And substitute in 0, cos(2∏(0-3))H(0-3) - cos(2∏(0-6))H(0-6) is...
15. ### Heaviside and Laplace Transforms

Homework Statement Rearrange f(t) using Heaviside Step Function Then Rearrange it so that the Laplace Transform can be written down Then, Write the Laplace Transform of f(t) Homework Equations The Attempt at a Solution So my first step is as follows... Using the basic Piecewise Function...
16. ### Laplace Transform of ODE

Could you possibly do this... y'' + 4y' + 3y = f(t) y'' + 3y' + y' + 3y = f(t) d/dx [y' + 3y] + [y' + 3y] = f(t) let u = y' + 3y u' + u = f(t) Would that be correct?
17. ### Laplace Transform of ODE

Thanks for that.
18. ### Laplace Transform of ODE

Homework Statement ODE: y'' + 4y' + 3y = f(t) f(t) = (?? HELP - What's the mathematical term to describe these? I can't seem t o find it in my notes :cry: ) 1, 0 ≤ t < 2 t², 2 ≤ t < 3 0, t ≥ 3 Write a brief description on how you would solve this ODE using Laplace transforms. Also use the...

20. ### Unit Vector Magnitudes and Forces

So essentially, balance out the forces... Basically something like... ForceTotal = ForceAB + ForceAC + ForceAD 2kN(eAB) = ForceAB = 1.1094i - 1.6642j + 0k
21. ### Unit Vector Magnitudes and Forces

Homework Statement http://prntscr.com/p7dxt Here's a screenshot of the revision question. Homework Equations The Attempt at a Solution Co-ordinates of each point A, (0, 60, 0) B, (40, 0, 0) C, (-40, 0, 40) D, (-60, 0, -60) Position Vectors rAB, 40i + -60j + 0k rAC, -40i + -60j + 40k...
22. ### Simply Supported Beams Loads and S/BMD's

Oops, here it is: http://prntscr.com/jg37y
23. ### Simply Supported Beams Loads and S/BMD's

I've done the shear force diagram, is this right? Some reason I can't edit previous posts or the thread.
24. ### Simply Supported Beams Loads and S/BMD's

Alright I've redone it, http://prntscr.com/jdu7d The next step is to draw bending moment and shear force diagrams. I'll post when I've got them.
25. ### Simply Supported Beams Loads and S/BMD's

Hmm, I think I have actually interpreted this question wrong. Is this image showing one 50kN load being distributed uniformly THEN being triangularly distributed. AND a 200kN point load? (I've been viewing it as two separate loads. I got 225 by (50kN * 9m)/2 (Uniformly distributed load)
26. ### Simply Supported Beams Loads and S/BMD's

Homework Statement Here is the Simply Supported Beam with a uniform and triangular load. http://prntscr.com/jd6b2 Homework Equations The Attempt at a Solution Newest attempt: http://prntscr.com/jdu7d Current Step: Shear Force and Bending Moment Diagrams.
27. ### Orsat Analysis on Furnace burning

Homework Statement Consider a continuous, steady state process to produce hydrogen in which the following reactions take place: C6H12 + 6H2O -> 6CO + 12H2 (desired reaction) C6H12 + H2 -> C6H14 (undesired reaction) In the process 220 mol of C6H12 and 840 mol of H2O is fed into the...
28. ### Chemistry Process Engineering - Mole Ratio and mole fractions

Alright, because this was a practice exam question (not homework), just thought that it'd give you all the information you'd need to know (and that the 'formula' for toluene wasn't given to you). So there is no way you can do it without the molecular mass of Toluene? (or calculate it with the...
29. ### Chemistry Process Engineering - Mole Ratio and mole fractions

Homework Statement A mineral slurry contains 3 components, solids, liquids and toluene. The slurry has 20 wt% solids and 80 wt% liquid. In the liquid portion of the slurry the mole ratio of toluene to water is 1:5.67 Determine the composition of the slurry (solids, toluene and water) in...
30. ### Thevenin Equivalent Explanation Request~

Homework Statement http://img507.imageshack.us/img507/6493/f7868b61c6cb4d6084fa5ba.png [Broken] Homework Equations The Attempt at a Solution I've tried to deduct how my textbook has actually done this Thevenin Equivalent. No one in my class (that I've come into contact with...
31. ### Magnitude of Cable Tensions and Compressive Force

How do I find them?
32. ### Centroid of a C-Shape

Yeah, I was probably thinking more about a centroid of a mass, but even then, there's still the donut which proves me redundant.
33. ### Magnitude of Cable Tensions and Compressive Force

Homework Statement http://prntscr.com/fehze There's a diagram with a rough free body diagram implemented. Homework Equations This is what I'm really unsure about. The Attempt at a Solution Finding Compression at BC: mg*sin(60) = 8495N Tension AC = mg*cos(25) = 8890N Not...
34. ### Centroid of a C-Shape

This is what confused me, does this mean the centroid is not on the shape itself?
35. ### Centroid of a C-Shape

Homework Statement http://prntscr.com/fcbm8 Find the centroid - All dimensions are in mm Homework Equations xbar = (A1X1+A2X2) / (A1+A2) Similarly for Ybar I assume The Attempt at a Solution I got the y co-ordinate to be 20.428mm, and would assume that the x coordinate...
36. ### Shear Force Diagrams and Bending Moment Diagrams

Homework Statement http://img189.imageshack.us/img189/9131/22465062cfdd4934b51d7f5.png [Broken] Hopefully the image isn't too difficult to decipher... Basically a beam balanced on to pin jointed pivots with 6 metres in between each one. Homework Equations ƩFy = 0 ƩFx = 0 ƩMP = 0...
37. ### Acceleration on a Frictionless Wedge

Homework Statement Two masses m1 and m2 (m1 > m2) are connected over a wedge shaped block. Assuming both inclined planes are frictionless along with frictionless and massless pulley, calculate an expression for the acceleration of the system. Here's what it sort of looks like...
38. ### Block Acceleration up an Inclined Plane

Should I actually be getting a figure here as an answer or an equation?
39. ### Block Acceleration up an Inclined Plane

Mm, because, I have no idea really on how to implement static as well as kinetic friction into this problem :/
40. ### Block Acceleration up an Inclined Plane

Could I use the same principles for this question? http://img844.imageshack.us/img844/6641/f5fec6746b9c42289610ba1.png [Broken]
41. ### Block Acceleration up an Inclined Plane

Ugh all because of one mistake which I thought wasn't D: Thank you so much!
42. ### Block Acceleration up an Inclined Plane

So instead of ma = m*g*sinθ - μ*m*g*cosθ it should be... ma = m*g*sinθ + μ*m*g*cosθ Which'll give me 1925N of force downwards... Then doing the same thing, I'll have 3500 - 1925 = 200a a = 9.625m/s^2
43. ### Block Acceleration up an Inclined Plane

so basically, what I would do is use that equation I've got down there: ma = m*g*sinθ - μ*m*g*cosθ 200a = 200*9.81*sin(30) - 0.35*200*9.81*cos(30) a = 1.9315 down hill Then... F = ma... = 200 * 1.9315 = 386.3 3500 - 386.3 = 200*a(uphill) a = 15.5685m/s^2 Which is ridiculously fast, but...
44. ### Block Acceleration up an Inclined Plane

Homework Statement A cable is pulling a 200kg block up an inclined plane elevated at 30 degrees with 3.5KN of force. How fast is the block accelerating at? θ = 30 g = 9.81 m = 200kg μ = 0.35 F = kN Homework Equations F = ma The Attempt at a Solution Wasn't sure how to do this problem, I...
45. ### Work done by the Friction Force

Yes, you are correct, I am trying to find the net work done. Since friction works in the opposite direction of which work does, I assume my friend is correct with his formula. Work = mgx(μcos(θ) - sin(θ)) Work = Fx Friction Force = -Fx
46. ### Work done by the Friction Force

Well, I'm not 100% sure, but it's basically, the amount of energy done by something? In anycase, is my Attempt correct? My friend did it, and he got Work = mgx(μcos(θ) - sin(θ)) not Work = mgx(μcos(θ) + sin(θ)) Cheers
47. ### Work done by the Friction Force

Homework Statement Find the work done by friction force as it slides down an inclined plane in terms of... m (Mass) x (Displacement) μ (Friction Coefficient) θ (Angle of the inclined plane) Homework Equations ƩFnormal = mgcos(θ) ƩFhorizontal = mgsin(θ) ƩFfriction = μFnormal -...
48. ### Initial Speed of a Projectile

After literally, 3 hours of arithmetic. We got the final answer.
49. ### Initial Speed of a Projectile

Homework Statement Find the initial speed (Vo) in Projectile motion in terms of Gravity (g) Height (H) Range (R) Homework Equations Nothing has been given, however, have found these so far... Initial Velocity = sqrt((1/2 * g * R^2)/(cos2θ * (R * tanθ + H)) And a few others which are...
50. ### Calculating Gravitational Acceleration

It was recorded on a Digital Camera and I viewed it through Windows Movie Maker. I watched it again several times it's definitely within the 60 - 70 millisecond range.