Choice Definition and 667 Threads

Hi can somebody tell me the answer they think is correct for the following multiple choice questions: Homework Statement 1) A uniform rod is attached to a wall by hinge at one end. Initially horizontal, the rod is released from rest to swing downwards. Consider the torque about the hinge...

Hi guys, I need an advise. I would like to start a Phd in physics, but I have not decided in which field yet. My curriculum is in theoretical physics, and my thesis was in cosmology, but I want to change the research field. I am looking for something theoretical that: 1)Still has...

I know the Delayed Choice Experiment has been beaten to death in the forum. But I was wondering if anyone can answer this question. Would the results of the DCE seems so odd if we accept that light is really a spread out wave. That is assuming that the particle nature light is really just...

Many physicists (especially experimentalists) seem puzzled by the delayed choice experiments (DCE), because, as they argue, such experiments seem to change the past. Here I discuss DCE from the point of view of (not 1, not 2, not 3, but) 7 major interpretations of quantum mechanics: 4 variants...

Hi there, just wondering what this could mean: "Remark: AC is trivial for |I|=1, since A non-empty means \exists x st x \in A . Similarly for |I| finite (induction on |I|)." I is the index set. As in, our sets are {A_i with i in I}. I'm really not sure what this explanation is getting...

Homework Statement Trying to find out correct answers to multiple choice. Homework Equations None The Attempt at a Solution I have an important physics test coming up and I tried the multiple choice questions from a past paper, but unfortunately there is no memo. Could someone...

A boy traveling on a skateboard steps off the board perpendicular to its motion. After stepping off, the boy lands on the ground and comes to rest. Which one of the following statements is INCORRECT? A The boy exerts an impulse on the ground on impact B The ground exerts an impulse on the...

We're faced with a tough decision. It's about Maxwell, the dog featured in https://www.physicsforums.com/showpost.php?p=1632392&postcount=30". He has bladder cancer and we took him to the vet today for a check up. He recently started dripping urine and blood. The ultrasound shows that...

I'm doing some practice multiple choice questions for my class and I would like to check my answers for some ones I wasn't entirely sure about. Any explanations would be really helpful. 1)What is the acceleration of an object of mass 4.5*10^-5 kg with a charge of 9*10^-9 C under the influence...

Yo yo yo. What up homies? I am once again humbled to be in need of your gracious assistance. I did all the work this time. I would just like some fresh minds to double check. I am driving two relays with http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=FMMT493CT-ND" is the...

For the degree I'm working towards (B.S. Math, minor Physics) I have to take 2 semesters of 2 different sciences. Obviously, physics will cover one of the sciences... I'm currently taking a chemistry class. I'm not finding it very interesting. Should I just go ahead and do a second...

Where can I find the proof of the claim that Zorn's lemma is equivalent to the Axiom of choice?

What must be true for two objects of the same material to have the same internal energies? (Choose all that apply) a. The masses of both objects must be equal b. Both objects must have the same density c. The temperatures of both objects must be equal d. Separate objects cannot have...

I am an international physics PhD applicant, and my intended field is experimental condensed matter, and have interest in nanomaterials and devices, electronic materials and devices, and semiconductors. I have received two offers from OSU and UFl, and other programs that are still reviewing...

I am an undergraduate physics major and I have a choice of taking linear algebra or differential equations in the fall. I was wondering which class would benefit me and my choice of a major more. Obviously I will talk this out further with my advisor, but I am looking for some outside opinions...

Homework Statement I'm getting different results when choosing my u & dv for Integration by Parts on the following integral: \int 2x^3 e^x^2 dx (Note, the exponent on 'e' is x^2) This yields the correct solution: u = x^2 dv = 2x e^x^2 dx du = 2xdx v = e^x^2 However, I have tried using...

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Homework Statement Multiple choice question about a modulus function, which statement is false? Below is the multiple choice question about a modulus function (the domain of the function is all reals): Which one of the following is not true about the function f(x)= | 2x+4 | : A. The...

I think the title pretty much sums up my question. I would like to get into the most prestigious grad school that I can (particularly MIT) but am worried that my choice in undergrad school might not be prestigious enough to get into a higher profile school. Do the ivy league(rs) really just...

Homework Statement 1. If A is a real symmetric matrix, then there is a diagonal matrix D and an orthogonal matrix P so that D = P T AP. a. True b. False 2. Given that λi and λj are distinct eigenvalues of the real symmetric matrix A and that v1 and v2 are the respective eigenvectors associates...

Hi can someone please help me with these multiple choice questions A sphere of mass M, radius r, and rotational inertia I is released from rest at the top of an inclined plane of height h as shown above. 1. If the plane is frictionless, what is the speed vcm, of the center of mass of...

Determine whether the given set S is a subspace of the vector space V. A. V=P5, and S is the subset of P5 consisting of those polynomials satisfying p(1)>p(0). B. V is the vector space of all real-valued functions defined on the interval [a,b], and S is the subset of V consisting of those...

Here is the question 5. A long board is free to slide on a sheet of frictionless ice. As shown in the top view above, a skater skates to the board and hops onto one end, causing the board to slide and rotate. In this situation, which of the following occurs? A) Linear momentum is...

A standing wave pattern is created on a guitar string as a person tunes the guitar by changing the tension in the string. Which of the following properties of the waves on the string will change as a result of adjusting only the tension in the string? 1) Speed of the traveling wave that...

Hello everyone I am going to be applying for PhDs this year and have been looking around at what is available. I'm finishing a masters in physics (in the UK) and I have tried to tailor it in the last year so that I have a medical physics/biophysics flavour to it through research projects and...

Dear All, I'm in the process of looking for a PhD position in Theoretical Physics but I'm unclear about a few things. 1) I still don't really know what I really want to do. The only thing I am sure of is that I want my research to help me in my understanding of ideas which I regard as...

Is more choice better? Ten years ago the answer seemed obvious: Yes. Now the conventional wisdom is the opposite: lots of choice makes people less likely to choose anything, and less happy when they do choose. In the The Paradox of Choice, Psychologist Barry Schwartz discusses the phenomena...

On a level practice range, a 46 g golf ball is struck by a golf club and leaves teh ground witha speed of 72 m/s at an angle 40 degrees above the horizontal. how much work was done by the golf club on the golf ball? a. 32 J b. 120 J c. 230 J d. 520 J e. 3300 J It's just...

Hi everyone, we recently covered some implications of the AC and are now to prove the followings statements with the help of the AC or one of its equivalent: (1) Every uncountable set has a subset of cardinality \aleph_1 (the least initial ordinal not less or equal than \aleph_0, the latter...

a strobe photograph of a car moving along a straight road shows the interval between each successive image to be diminishing. If the direction of motion of the car is taken as positive, which of the following are negative? a. the speed of the car b. the average velocity of the car c. the...

I'm trying to prove that the axiom of choice is equivalent to the following statement: For any set X and any function f:X\to X, there exists a function g:X\to X such that f\circ g\circ f=f. I was able to prove that the AoC implies this, but I'm having a harder time going the other...

Which will be the best Choice Within Ten Years?? Right now, I'm sudying in ninth grade, but I get too worried about what to study and which field I want to work in. Mabey I'm getting a bit too crazy about this, but I think it will be good to make up my mind beforehand. I've shortlisted five...

I am here hoping for some geeky advice on a camera for my wife for Christmas. The most important features are going to be speed (meaning "boot up time" and time to capture the image after pressing the button) and taking good pictures in lower light without her having to think a lot about...

I want to Commercialize Science: just not discover it: Effects of Career Choice I am in need of my major advice. My father is a Political Scientist and Economist, and he has personally wrote on current and future political and economical tyrannies. He sees the formation of a much more...

Homework Statement The moment of inertia of a sphere rotating about an axis through its center is (2/5)MR^2, where M is the mass and R is the radius of the sphere. What is the moment of inertia of the sphere about an axis on the edge of the sphere? a. 0.4 MR^2 b. 1.4 MR^2 c. 0.9 MR^2...

Hello again everyone, looking for some advice from people who are/have studied at university; The problem I'm having is that the university I'm seriously considering studying at for an MSci (in physics) is UCL however I'm not sure about the course... Indeed UCL has a fantastic reputation...

#1) A child ties a .25kg rock to the end of a string and whirls it at a constant speed in a horizontal circle of radius 75 cm. What, approximately, is the maximum speed at which the stone may be whirled if the string will break for a tension exceeding 300N? A. 10 m/s B. 13 m/s C. 15...

Zombie Slaying Weapon of Choice... I did this a couple years ago but let's do it again. If the Zombie Apocalypse came what would be your zombie slaying weapon of choice? Vote and post a description and/or reasoning if you would like. I'm trying to add a poll here but I haven't done it...

Homework Statement 1. Which of the following is not a linear transformation from 3 to 3? a. T(x, y, z) = (x, 2y, 3x - y) b. T(x, y, z) = (x - y, 0, y - z) c. T(x, y, z) = (0, 0, 0) d. T(x, y, z) = (1, x, z) e. T(x, y, z) = (2x, 2y, 5z) 2. Which of the following...

What are your necessary tools when it comes to the world of science ? Myself... 1) Pentel P207 Mechanical Pencil 2) Sharp EL531 Scientific Calculator

First of I'd like to introduce myself. My name is Jeroen, I am HUGE fan of physics and science. It's frustrating with physics for me because I am very visual person everything is video or modeling in my head, and I have a very hard time converting back and forth so I hope you guys don't mine...

Here is a multiple-choice question. It is the exact wording of the question. A true statement regarding the graph of y=inverse relation of f(x) is (a) an x-intercept occurs at (1,0) (b) a y-intercept occurs at (0,-1) (c) The point (-2,3) becomes (3,-2) (d) The graph of the inverse...

Homework Statement Somehow Larry got stuck in the middle of a room with a frictionless floor. Larry is at rest. How could Larry start moving to get to the edge of the room? A. Push on the floor with his hands or feet. That way the floor could exert a force on him and Larry could...

Given the current state of the jobs market, would the current Electrical Engineers still encourage new Engineering majors to select EE? Thanks!

Hi all. I am currently a Junior attending SUNY-Stony Brook as a math major. This coming fall semester I have a very good opportunity before me: I can either take the undergrad abstract algebra course (textbook: Contemporary Abstract Algebra by Gallian), or I can take the graduate abstract...

I am trying to decide between two different graduate math classes in the fall. These are the only classes that sound really interesting to me, as well as fitting in with the rest of my schedule. My other courses will consist of several physics type courses, notably, Jackson's electrodynamics...

Well, I'm new to the forums and (must say, great forum you guys have here) I am in a bit of a dilemma here. I have read many of the comments in this thread and some have lead me to have my usual doubts about engineering and technology. I'm attending the University of Houston in Houston Texas...

http://i42.tinypic.com/97vehc.jpg ^It's all in there. Thanks in advance =]

I've been thinking about this weird experiment for a while and came up with a couple of insights: * This experiment presents before us the paradox between our concept of time, and the photon's nature of living outside of time. For the photon, the idler and the signal were measured at the...

So let's say we have an offworld mining colony somewhere in the solar system and we want to build an orbital refinary and fabrication plant to process the ore, for such an application which choice for power would be more practical, solar thermal or nuclear? How large would they need to be?