# Search results

1. ### Determine the maximum allowable weight of a load supported by chains.

Draw a free body diagram and you will see how the 3rd chain comes in. Point A is a good place to isolate for a FBD.
2. ### Morh's Cicle with two shear forces

What do you mean by torques? Take a square element and draw all the shear and normal forces on it. Pay attention to which sign convention that you are using in your course. Start out by calculating the normal and shear stresses for each side (sigma x, sigma y, and tau xy). You are given...
3. ### Heat Transfer Through a Cylinder

Can you post the actual problem statement? I think if you draw a thermal circuit, it will give you a good map to solve the problem.
4. ### Steam tables and enthalpy

It would help if you could post the complete problem statement. For these types of problems, it usually helps to draw out the P-V and T-S diagrams. I suspect the equation relating enthalpy and work will help here, it should be somewhere in your text
5. ### Simple AutoCAD question (plates)

I suggest you use the helpful within autocad. Or even google tutorials on it. If you sketch what the problem is asking on paper, then it can be done on cad. Of the top of my head, some of the commands that you should look up on the help are snap, zoom, grid, Osnap, layers, dimensioning, and...
6. ### Checking for time invariance

Homework Statement Consider the following input-output relationship: y(t) = \int_0^\infty e^{-\sigma}x(t-\sigma) d\sigma A) Is the system time-invariant? B) Find the output y(t) when the input to the system is x(t) = \mid t \mid , -\infty < t < \infty Homework Equations These are the...

Look at how the coordinate system is defined in the problem. Which direction is the x-component of the tension CD pointing?

Can you post your solution to the problem? The solution you posted is probably from the solutions manual which is meant for instructors, so they skip a lot of steps. It doesn't even show a FBD, so obviously it's difficult to understand their solution.
9. ### Op-Amp Question

The potential difference for the 30k resistance is just going to be the V- of the first op amp subtracted from the V- of the 2nd op amp. I'll leave it to you to find what those are.
10. ### Op-Amp Question

Your image of the op amp is gone. Can you upload it again?
11. ### Engineering Basic Circuits Question

Yea, you don't assume polarities for resistor voltages. What I meant about assuming polarities for voltages sources, is when the question asks you find the polarity of the voltage source. In your case, the polarities are given.
12. ### Engineering Basic Circuits Question

Your image isn't showing up, but i'll try to answer your q's without. You assume a direction for the current, if the direction is not given. If they don't give you the polarity of the voltage source, then you just have to assume which side is + or -.
13. ### Thermodynamics Problem

Start out by drawing an T-s, P-V, and T-V diagram, to better see the cycle
14. ### Op-Amp Question

Ask yourself this question. What are the voltages (V+,V-) at the op amp terminals. In an ideal op amp V-=V+ Sorry, I was in the middle of editing and trying to answer your questions till the phone rang... The 70, 30, 60 resisters at the top are connected by the same node. Yes, Vo=V- at the 2nd...
15. ### Shear Moment Diagram

Can you explain you're work. The images don't show up too well, and i don't see alot of work explaining the graphs. I'm familiar with the method you're using, guess you could call it a short-cut. Also you can try going through the problem again using the differential equations that you...
16. ### Find the height of the water

Let's make life easier by using gauge pressure . Also you defined Z1 and V2 incorrectly.

Apply conservation of mass and conservation of energy.
18. ### Please visst the link and can someone help me to answer the question. I am lost.

Homework Statement Homework Equations The Attempt at a Solution Fill that out, so that someone can see what your thinking. Start by finding the centroid of the gate, then locating the center of pressure.
19. ### Hibbler dynamics problem 13-97

Can you post a diagram of the problem>?
20. ### Engineering Circuit with capacitor, current source, voltagr source and a switch

Analyze the circuit at t = -0, t= +0, t=0 separately. I saw that you kind of did it that way, but just label just label it so that its easier to follow your work. And what's your question?
21. ### Need help with thermodynamics

As russ_watters pointed out, there is another variation of the ideal gas law. The one you posted PV = mRT is one variation, and you can rewrite the equation to solve this problem. It should also be in your textbook. Look at the units that you have. You are given ft and the answer is in psig...
22. ### Need help with statics problem

M = F*d only applies if your moment arm is perpendicular to the line of action of the force. This is a 2-D problem so you have 3 equations that you can write down. Once that's done, you can see how to solve for the angle.
23. ### Thermodynamics Question

Start with the first law of thermodynamics. Probably a few assumptions in the problem, like KE and PE = ? Also you'll need the charts, probably in the back of your text.
24. ### Dynamics, plane drops mass trajectory question

Just start with the equations of motion under gravity, or you could use the already derived free fall equations, but its better start from scratch and derive it. They tell you that speed is constant, so what are the acceleration components?
25. ### Engineering Need help w/ circuit analysis

The currents in your KVL equations are NOT all Ix. Ix is the current through that bottom right resister and will not be the same once it passes through that first node. Also what are the units for the resisters, kohm or ohm?
26. ### Hydrostatics question

Why do you need to differentiate with the hydrostatic relation?
27. ### Engineering Circuit with DC & AC sources

upload your image on imageshack or something. Sometimes it takes awhile to get an image approved if you upload it on the forum
28. ### Kinematics of a Particle Tangent-Normal components

Homework Statement http://img136.imageshack.us/img136/1930/carrs8.th.png [Broken] Homework Equations a = (v^2/p) en + (v*)et a- accel v-velocity en- inward normal et- unit vector along tangent v*- tangential acceleration p- curvature The Attempt at a Solution FOr the first part I just need...
29. ### New to op-amps

Nothing wrong with Summing Amplifier equation. I would have used it too, just because of laziness.:rofl: Well if you want to check it, go back and do it using nodal analysis and see if you get the same answer.
30. ### Engineering CIRCUIT ANALYSIS: 2 resistors, Indep. Current Source, V.C.C.S - find v0

Oh alright. So yea, he's just not finished with the problem yet. Hope he checks back. :uhh: