# Search results

1. ### I Interpretation of the Reynolds Transport Theorem?

Background: I am taking an undergraduate fluid mechanics class. I seem to have a misunderstanding with my interpretation of Reynolds Transport theorem (RTT), which I have written below: \frac{DB_{sys}}{Dt} = \frac{\partial}{\partial t}\int_{CV}\rho bd V +\int_{CS}\rho b \vec{V}\cdot...
2. ### Binding energy / mass deficit of Earth-moon system?

Homework Statement Consider the earth-moon system (whose constituent pats we take to be the earth and the moon separately). a) Compute this system's gravitational potential energy (in joules) and the mass deficit (in kilograms). The radius of the moon's orbit is 384,000 km, and its period is...
3. ### Induction Problem (Polya)

Homework Statement Consider the table: 1 = 0 + 1 2 + 3 + 4 = 1 + 8 5 + 6 + 7 + 8 + 9 = 8 + 27 10 + 11 + 12 + 13 + 14 + 15 + 16 = 27 + 64 Guess the general law suggested by these examples, express it in suitable mathematical notation, and prove it. Homework Equations [/B] It's clear that if...
4. ### Programs Intersection of Physics and Applied Math?

Hello all, I am interested in both physics and applied math. One of my professors is willing to work with me to get into a great applied math school, but I don't want to abandon my passion for physics. Is there work being done at the intersection of applied math and physics? Is it reasonable...
5. ### Solving Simultaneous Inequalities

Homework Statement [/B] I am trying to solve the simultaneous inequalities (1) and (2) shown in the following image. The solution is provided, but I'm not sure how they solved for it. [PLAIN]http:// Homework Equations N/A The Attempt at a Solution [/B] I tried to solve this set of...
6. ### Linear Algebra, Determine the Volume of the Parallelepiped

Homework Statement What is the volume of the parallelepiped with vertices (3, 0, −1), (4, 2, −1), (−1, 1, 0), (3, 1, 5), (0, 3, 0), (4, 3, 5), (−1, 2, 6), and (0, 4, 6)? Homework Equations The volume of a parallelepiped is given by the triple scalar product, (a × b) ⋅ c The Attempt at a...
7. ### Good Laptop for Engineering?

Hi all, What laptop would you recommend for a mechanical engineering student? I really like Mac but I hear that engineering software is almost all Windows. Are there any good engineering laptops for around \$1,000 that you could recommend?
8. ### Does anyone work in the space industry?

If anyone here works in the space industry, would you be willing to tell me about the most important credentials and qualities someone needs to work in your field?
9. ### Get my second bachelor's or go for Phd?

Hi all, I've asked for a lot of academic guidance before, so thanks for all the advice up to this point and going forward. Here's the background: I'll be graduating this coming May with a double major in mathematics and computer science. My true passion tends to lie with engineering and...
10. ### Data Corruption from Sensors with Long Wires

Hi all, Hopefully this is the right subforum. I have a question related to Arduino sensors. Q:Generally, when do you need to be worried about losing data from having long wires from your sensor to your Arduino board? Details:For example, I've been looking at two sensors. Sensor 1: MLX90614...
11. ### Why do enantiomers rotate polarized light?

We are currently learning about enantiomers in organic chemistry class. So far, we've covered what makes an enantiomer, the concept of chirality, optical isomer naming systems, and the physical and chemical properties of enantiomers. One of the physical properties listed is that enantiomers...
12. ### Master's vs PhD

Hi everyone, I'm currently researching graduate schools in mathematics. I would like to go for a PhD. My question is, do I apply directly to the PhD program? Or do I apply to the Master's program and apply for the PhD afterwards? What do people normally do?
13. ### Solenoid Electricity Generator

Hi all, I'm trying to generate enough current using a solenoid to intermittently power an LED. My plan is to buy some enameled copper wire and wind it around pipe. This will be my solenoid. Then, magnets will be pulled through the pipe on string or what-not and, by Faraday's Law of Induction...
14. ### Does the space industry hire mathematicians?

Hi all, I'm currently an applied mathematics student in my third year, and I plan to attend graduate school for pure or applied math. Physics and engineering deeply interest me, so I'm naturally drawn to the aerospace industry. Dazzling leaders like NASA and SpaceX are truly inspiring, and it...
15. ### Schools Working through college?

Hi all, It's my third year of college studying mathematics. Some of the upper level courses are more challenging, although I'm making it through them. After school, I want to get a masters or PhD in mathematics. I currently work 10-15 hours a week, and sometimes this adds a lot of stress...
16. ### Is "Western thought" primarily Aristotelian or Platonic?

I was arguing with my friend over this topic. In your opinion, whose thoughts influenced western civilization more, Aristotle or Plato?

Hi all, I'm going to ask my boss to pay for some percentage of my graduate school. He has hinted before that this might be a possibility. It won't be totally out of the blue. So, I have a few questions for you. 1) Have any of you had a similar arrangement? 2) If so, how much did your...
18. ### Intensive GRE study or job over summer?

Hello all, I'm going into my senior year of applied mathematics this coming Fall semester. My adviser recommended that I take the GRE before Fall semester starts so that I can have my Grad school applications in by the December deadline. My question is as follows: Would it be better to study...
19. ### Simple Analysis Question

Rudin makes the following statement in his Real and Complex Analysis, page 3: If z = x + iy, x and y are real, then ez = exeiy. Hence |ez| = ex. I don't understand what's happening here. If I draw ez on coordinate axes with imaginary numbers on the y-axis and real numbers on the x-axis, I get...
20. ### Income Distribution Data Sources for Statistical Analyses

Hello all! I'm hoping you will be able to direct me to sources of raw income1 / employment data. Hopefully this thread can be a help to others who have similar needs in the future, as well. (I did a quick search for a similar thread and didn't find anything - please correct me if I'm wrong.)...
21. ### Is 1/4π built into G, the gravitational constant?

We went over Coulomb's law today, which can be stated as (1/ε0)(1/(4πr2))(|q1q2|) This equation is very similar to Newton's law of gravitation, but it contains 1/4pir^2. This makes sense, because the electric force is being diluted over the surface of a sphere. Is 1/(4πr2) built into G as well?
22. ### Favorite Self-Authored Riddles?

Hi all, I love riddles and occasionally try to write them. Here's one that I like because it rhymes (although it's super easy). Small as a pebble, deadly as a boulder Used by the rebel, but mostly by the soldier What am I? Have you made any riddles that you'd be willing to share?
23. ### Admissions HELP! Applying for an REU

Hi everyone, I'm in the process of applying for an REU (undergraduate research experience). The application requisites call for TWO letters of recommendation from faculty members. In my excitement, I was able to obtain THREE letters of recommendation. - On the one hand, I don't want to appear...
24. ### Principle of Least Time Question

Hi everyone, I'm taking my second semester of calc based physics this coming spring. I have a question in optics stemming from my reading of Feynman's lectures on physics. He gives a rough definition of Fermat's principle of least time as follows: "... out of all possible paths that it might...

Hi all, I want to buy my mathematics professor (who is also my adviser) a gift as a token of my gratitude for his hard work. Do you have a favorite math trinket/toy that you would recommend? Note: He loves abstract math. His dissertation was in topology. Thank you!
26. ### Should I take 'Physics of Sound'?

Hi all, This interim there aren't any good math/physics classes at my school, so I'm considering taking "Physics of Sound" at a nearby university. I'm wondering if it would be worth my time/money. I want to go into engineering or teaching (either way, grad school is ahead of me). How hard is...
27. ### A implies B?

Homework Statement Suppose someone says to you that the following statement is true: “If Jack is younger than his father, then Jack will not lose the contest.” Did Jack win the contest? Why or why not? Explain. Homework Equations Truth table from textbook: A--------B--------A implies B...
28. ### Vector Question - u = u1+u2 where u1 is parallel

Homework Statement Let u = i - 2j, v = 2i + 3j, and w = i + j. Write u = u1 + u2 where u1 is parallel to v and u2 is parallel to w. (See question 41.) Homework Equations Properties of vectors. Question 41: https://answers.yahoo.com/question/index?qid=20090923151849AARqpWR The...
29. ### What is crystal momentum?

Hello, Could someone please explain crystal momentum in understandable terms? Thanks, EV