1. ### Use-case diagram

this user will only use this function when something extraordinary situation, and that's how I stated it in the use case diagram. Is it a bad method of stating this way?
2. ### B Do any 3D Venn diagrams exist that have no 2D analogues?

If we were to use three-dimensional spheres to represent sets, could a 3D Venn diagram be constructed that could not be drawn as a normal 2D Venn diagram without changing the relationships between the sets?
3. ### I Sorry but I'm still going nuts over the twin paradox

I feel a little guilty writing this post because I'm sure there are people here who are tired of answering questions about the twin paradox, hence the FAQ post on the subject, but there's something which is still nagging me. First I have a question about the FAQ post itself. Toward the bottom of...
4. ### A Grotrian diagram of Hydrogen

Why is it that in Grotrian diagram only the 4p->3s is not allowed, but the 4s->3p, 4p-> 3d and 4d-> 3p are allowed ? I'm following the rules of Δl=±1 and Δm=0,±1 and they give the same numbers. I also tried with Δj=0,±1 and still the same. Grotrian Diagram for Hydrogen for n=[1,4]...
5. ### Band diagram, conductivity tensor

Hello! Does anyone have an idea of how can I obtain information from a band diagram about the directions along which the system conducts best and worst ? Thank you in advanced! :)
6. ### Diagram about potential difference over current

Homework Statement [/B] Homework Equations [/B] I = G * U The Attempt at a Solution [/B] Hello, i know the solution is 5.0 A/V but i dont know if my way of solving this was correct. I rearranged it to G= I/U and solved this equation for all the values in the table and then added them...
7. ### A problem with momentum

Homework Statement want to find the direction and moment of this diagram. Homework Equations The Attempt at a Solution [/B] I really do not have any idea about this question. So If someone helps, It'd be great.
8. ### Studying How to remember diagrams?

Hello to everyone, I am an undergrad mechanical engineering student. Currently in 4 semester. I have this one major problem. I cannot memorize facts and diagrams. We have this subject, production technology, which consists of lots and lots of facts and for me an overwhelming amount of...
9. ### RAM memory diagram using decoders

Homework Statement Draw a block diagram of 32kx8 bit RAM memory using decoders DEC 3/8 and memory components 8kx8 bit. 2. The attempt at a solution First we find the number of memory components: N=\frac{32kx8}{8kx8}=\frac{2^{18}}{2^{16}}=4. The number of decoders is 32/8+1=5 There are 4...
10. ### Engineering Transformation of resistors in a circuit

Homework Statement From the circuit diagram ( http://postimg.org/image/lldnr7mf7/ ) calculate the net charge flown through the capacitor 2. Homework Equations 3. The Attempt at a Solution [/B] I actually don't need to solve the full problem as i understand how, what i have trouble with is the...
11. ### I How to draw figures and diagrams?

Hi! I have been doing some reading over the past 5 months on spacecraft dynamics and physics mechanics -dynamics . I want to create figures and diagrams such as those found in Orbital Mechanics by Curtis, Vector Mechanics for Engineers by Beer and University P|hysics by Young. Which software do...
12. ### Graphing the energy in an capacitor, coil and resistor

I need to graph the current energy on a resistor, capacitor and inductor they are all separate it is not a RLC circuit. This is what I know u(t) = sqrt(2)*220*sin(314*t+π/3) R = 10 Ω L = 3 mH C= 3 mF I have already calculated the current for each component, now I need to calculate the energy...
13. ### Programs used for creating scientific diagrams/illustrations

Would anyone happen to know what programs out there could be used to make this type of diagram/illustration? (image was found on this thread, btw) I've been wondering for a while as to how people make stuff like this, like the graphs they have in my math and science textbooks. I think knowing...
14. ### Shear force and bending moment diagrams question

Homework Statement In the image uploaded below, a boxed shaped object is shown. It is floating in water so the forces that act on it are buoyancy and gravity. The first and the last compartments are filled with evenly distributed weight. The middle 2 compartments are empty. Specifics are...
15. ### My Physics teacher presented a wrong diagram? (Explanation↓)

My Physics teacher told us to use a = g x sinθ during a lab trying to find how close we could calculate gravity using an inclined plane, a moving cart and a motion sensor to measure acceleration. He also drew a diagram next to the formula. I just wanted to confirm that his diagram was wrong, or...
16. ### Free Body Diagram of Car on Mountain

If a car is on top of a mountain moving with an initial velocity, will it only forces acting on it be the normal force counteracted by the force due to gravity?
17. ### Hourglass's weight

How does an hourglass's weight change while sand is dripping in it? (better be in a diagram)
18. ### How to tell if the components are in parallel or series

Homework Statement I need to work out the impedance of this notch filter, and what I really need is to know how to read the diagram, because if I can do that the rest isn't so hard. The diagram looks like this (I don't know if this uploaded right) So really, all I am trying to do is tell if...
19. ### Entity Relationship Diagram

I am doing a ER Diagram for a class and having a lot of trouble with a specific piece of the sentence. Anyway, here is the business requirements we are diagramming: The video rental company has several branches throughout the USA. The data held on each branch is the branch address made up of...