Class Definition and 942 Threads

  1. W

    MHB Which class has the greatest frequency and which has the least frequency

    The data represent the​ time, in​ minutes, spent reading a political blog in a day. Construct a frequency distribution using 5 classes. In the​ table, include the​ midpoints, relative​ frequencies, and cumulative frequencies. Which class has the greatest frequency and which has the least​ frequency?
  2. Math Amateur

    MHB Why is the Series Absolutely Convergent for Sequences in l^2(N)?

    I am reading Houshang H. Sohrab's book: "Basic Real Analysis" (Second Edition). I am focused on Chapter 2: Sequences and Series of Real Numbers ... ... I need help with an aspect of Example 2.3.52 ... The start of Example 2.3.52 reads as follows ... ... In the above Example from Sohrab we...
  3. S

    Python Updating attributes within a class

    I'm working on a sparse matrix class, where I'm creating an internal representation of a random matrix a la CSR (Sparse Matrix). 'A' signifies the non-zero elements in the matrix, 'IA' are the rowpointers and 'JA' the column indices of the non-zero elements. import numpy as np class...
  4. V

    Class Project: Marble Ball Launcher [Help]

    What I'm here to find out: I am in the early stages of a physics project to build a electric circuit or use an electrical source to power the force that will carry a marble throughout the mechanical portion of the project, going through linear acceleration and circular motion. I'm not sure what...
  5. E

    How could Class III Levers till be considered Levers at all?

    I thought the definition of a Lever was a machine that will decrease the force needed to do work by increasing distance. Since Class III levers always have a mechanical advantage less than 1, and they actually increase the force needed, how could they be considered levers at all? I don't get it.
  6. P

    How many students total are in this class?

    The book got 28 students, I got up, when I added up 2+3+4 etc. I got a bigger answer explain please, if I did it wrong. Thank - you in advance
  7. anorlunda

    What is the risk of infrequent events and outdated GPS systems?

    From today's news: https://arstechnica.com/information-technology/2019/04/gps-rollover-event-on-april-6-could-have-some-side-effects/ There is an entire class of risks that I could label "infrequent events". The mother of all of them was Y2K. (Y2K bad consequences were avoided via massive...
  8. T

    MHB Frequency Distribution: Time Reading Political Blog

    The data represent the​ time, in​ minutes, spent reading a political blog in a day. Construct a frequency distribution using 5 classes. In the​ table, include the​ midpoints, relative​ frequencies, and cumulative frequencies. Which class has the greatest frequency and which has the least​...
  9. C

    Class A Amplifier Sinusoidal Input/Output Relation

    My simplistic derivation below for a Class A amplifier shows that an AC signal at the input produces DC, fundamental, and 2nd harmonic terms at the output. This seems to contradict most the information I have found on this - which just states that the output is sinusoidal and of the same...
  10. nmsurobert

    I Spectral Class of Stars: Exploring Electron Transitions and Absorption Spectra

    I understand the process of electron transitions but I don't understand how or why these pictures are put together. If we're looking at the spectra of a star, why are this pictures shown as absorption spectra and not emission?
  11. C

    MHB Equivalence Classes: Solving Cbarker1's Problem

    Dear Everyone, $\newcommand{\R}{\mathbb{R}}$ I am struck in writing the equivalence classes. And the problem is this: Let ${\R}^{2}= \R \times \R$. Consider the relation $\sim$ on ${\R}^{2}$ that is given by $({x}_{1},{y}_{1}) \sim ({x}_{2},{y}_{2})$ whenever...
  12. L

    MHB Creating XML DTDs from UML Class Diagram

    The question first asks to generate a UML class diagram for a bus company, which I did in the attached image. The methods arent filled in. Then the Q asks to" generate several XML DTDS, with atleast 1 attribute in each DTD, and take care to represent associations between classes" Im familiar...
  13. H

    MHB Set vs Class: Exploring the Differences

    What the differences between set and class?
  14. TymerTopCat

    1st class lever question (I think) -- tilting antenna erection mechanism

    I want to build a tilting wireless internet structure that is 24 feet high, with a fulcrum at 6ft. The idea is when I want to work on the device (which is 24 ft in the air), I can just unlatch the mast and tilt the structure down and work on it. I would like to have the pivot (or fulcum) at six...
  15. Mr Davis 97

    Using class equation to show that intersection is nontrivial

    Homework Statement Let ##G## be a finite p-group and ##Z(G)## its center. If ##N \not = \{e\}## is a normal subgroup of ##G##, prove that ##N\cap Z(G) \not = \{e\}##.Homework EquationsThe Attempt at a Solution Since ##N## is a normal subgroup we can let ##G## act on ##N## by conjugation. In a...
  16. CaptainAmerica17

    Programs Don't like my calculus class, but want to be a math major....

    I am currently a junior in high school and recently, my guidance counselor has been asking me a lot of questions about what I want to major in. Within the last 6-8 months, I have been leaning heavily towards a math major. That was until I started my calc class this year... I'm in AP Calc BC...
  17. C

    Building a Mousetrap Car for High School Physics Class

    I am in a high school physics class and have been recently assigned a mouse trap. We were given a mouse trap, that is all, and sent out on our own to create one. The requirements for this specific mousetrap car are to go forward 3 meters, then backwards 2 meters, and finally forward three meters...
  18. J

    Calculating Effort Needed for Unevenly-Loaded Class 2 Lever

    Hi, I essentially have a class 2 lever, which holds an unevenly spread load. The lever itself (platform) is however an even weight throughout its length (except for the odd RSJ I've welded in for strength). This is an OLD machine, and hence we're going to build a bigger, stronger and higher...
  19. J

    Class 3 Lever: Non-perpendicular Effort

    Hi, We have a machine in our workshop in which we are modifying to relieve the amount of lifting force required by the hydraulic ram. This will subsequently reduce hydraulic system pressure which is the main goal. I'm trying to calculate the current configuration. It consists of a class 3...
  20. J

    MHB Number of students in a class at first

    There were m pupils in a class at first. After a week, 4 more pupils joined the class. a) Find the number of pupils in the class after a week in terms of m. my answer: m + 4b) There were 40 pupils in the class after a week. How many pupils were there in the class at first? my answer: no...
  21. J

    MHB How many girls were there in the class?

    There were 42 pupils in a class at first. After 6 boys left the class, there were 3 times as many girls as boys. How many girls were there in the class? My answer: 42 = (x+ 6) + 3x => x = 9the (x+6) is basically (boys + 6) So there are 27 girls and 9 boys? Did I do my work...
  22. Bobs

    Today, in our class, we received a trigonometric equation

    Today,in our class, we received a trigonometric equation ##\sin^{10}{x}+\cos^{10}{x}=\frac{29}{16}\cos^4{2x}## Here is my attempt:
  23. C

    I Switching to Math -- "If you are the 50th best student in the class"....

    I have discovered that, even when doing math problems, I don't actually think in math. I was just practicing for fun on Alcumus. The question was this: "If you are the 50th best student in the class and also the 50th worst student in the class, how many students are in the class?" The answer...
  24. S

    Designing circuits after 101 class

    Im just finishing up my first digital electronics class right now. I know how to design the logic for basic circuits and some slightly more complex ones. I don’t quite understand how to design actual circuits for a few reasons. 1.) When we design “circuits” in class, we just draw them without...
  25. isukatphysics69

    Series question in my Calc2 class

    Homework Statement Homework EquationsThe Attempt at a Solution Not sure what I'm doing wrong here that looks like what the series is showing
  26. Laurie K

    B Basic rule for Atmospheric Reentry of Glider Class vehicles

    The Chinese Space Station, Tiangong 1, looks very much like a glider i.e. a bit like the US Space Shuttle (solar panels are made of similar materials to Space Shuttle tiles with much less friction), as the German radar images show in the link below, so it most likely wasn't tumbling but yawing...
  27. K

    C/C++ Copy Assignment Operator for CarCounter Class

    Write a copy assignment operator for CarCounter that assigns objToCopy.carCount to the new objects's carCount, then returns *this. Sample output for the given program: Cars counted: 12 #include <iostream> using namespace std; class CarCounter { public: CarCounter(); CarCounter&...
  28. Gamma

    Laser Safety Glasses for Class II

    Hello, Community college teacher here. I was instructed to employ a laser safety program in my intro physics lab. We mainly use Class II lasers that came with the PASCO Optics table and Laser Ray boxes. One of my adjunct faculty uses Purple and green laser pointers which is classified as Class...
  29. RelativelyEmma

    Other Loving Physics But getting discouraged by staff, not the class

    Hello! Sorry if this is kind of long: I have an autoimmune disease and my grades occasionally struggle and sometimes I have to drop a class or two (though the dropping is more rare). I've been set on physics since I was 12 and love all my classes but here's the thing: between struggling with...
  30. L

    Studying Class average for my physics mid-term was 8/30, Seriously

    Hi guys. I would like to ask for a very general piece of advice. Last semester I had my first introduction course, mechanics. The course was extremely hard, but I managed to get an A. I was one of only 4 students in a class of 108 who got A. I'm not sure how I did it considering that I came...
  31. egetunc

    Looking for a project for modern physics class

    For my modern physics course our group(3 people) need a project to build in 12 week,(so not short, 2-3hours work for each person per week) Our topics are: Relativity Waves and Particles I Waves and Particles II Bound States: Simple Cases Unbound States: Obstacles, Tunneling and Particle-Wave...
  32. Stephenk53

    What to do in my spare class time?

    I am now in computer programming 2 at my school and in computer programming 1 I often had a lot of time to spare since I usually finish the class way ahead of time. So I am wondering what you guys think I should do in my spare class time. It does not need to be programming based but I would like...
  33. J

    MHB Congruence Class Proofs: Tips and Examples

    Hi, I have tried the question as attached. I am not sure if I am correct. You help is greatly appreciated. Thanks in advance!
  34. pairofstrings

    Class, Interface, Abstract, Static, Partial, Sealed

    Hi. What do I call Instance Classes, Interface, Abstract Classes, Partial Classes, Static Class, Sealed Class collectively? Thanks.
  35. Eclair_de_XII

    Courses I deciding what class to take this semester

    It's kind of unrelated to the curriculum of these two classes, by the way. Basically, I have a choice to take Microeconomics and Differential Geometry. While I do find the concept of applying my calculus and linear algebra skills to the latter course, I cannot help but feel that I have to take...
  36. Y

    Gain calculation of tube class AB output stage

    Hi I don't know if anyone here design tube power amps. I am calculating the gain of the class AB output stage of push pull tubes and output transformer. Class AB by definition has a small signal region that both tubes are working and is operating in pure class A. Only when input signal is large...
  37. Eclair_de_XII

    Courses What kind of class is differential geometry?

    This is my college's description for it: Differential Geometry (3) Properties and fundamental geometric invariants of curves and surfaces in space; applications to the physical sciences. Pre: Calculus IV, and Introduction to Linear Algebra; or consent. I was doing pretty well in all my...
  38. M

    Which physics class should I take first?

    So, I just finished Mechanics of Solids and Fluids and have the option to take 'Electricity and Magnetism' or 'Heat, Waves, Light in Modern Physics' next semester. 'Electricity and Magnetism' is the next class in the series but I didnt vibe well with my instructor, so I can take the other class...
  39. D

    Comp Sci Working with classes and vectors in C++

    Homework Statement Write a BinaryTree Class using these specifications: A Class Node represents a standard node of the tree with fields and a constructor like given below: int start, end; const Complex* value; //I will provide more information about Complex later because that was the...
  40. A

    I What is the formal definition of a Universality Class?

    Hi guys, I have been reading some of the literature recently concerning the Kardar-Parisi-Zhang equation and the words "universality" and "KPZ universality class" keep appearing. I already did a cursory wikipedia search on the subject, but it did not make much sense to me. Can you please...
  41. mishima

    Butane Combustion Analysis Demo for a High School Chemistry Class

    Hi, I'm a high school chemistry teacher trying to develop a lab experience demonstrating combustion analysis. This is usually something we go through theoretically during discussion of percent composition and empirical formula. I'd like to actually perform one. I was wondering if this could...
  42. D

    C/C++ Question about a specific class method in C++

    Create a class DecimalN which holds decimal numbers using dynamic arrays. Implement a constructor DecimalN::DecimalN(char* decimal) so that it can be created like for example DecimalN number("23.5698"). Create two class functions (methods) that given the number n it shift the number n places...
  43. D

    Comp Sci Using a custom constructor in a C++ class

    Homework Statement I am quite new to C++. I have completed my C course and am now taking a C++ course at my college. The first problem i encountered is with classes and custom made constructors. In the first part of the problem I am supposed to create a class with a field which is a dynamic...
  44. FallenApple

    I Homotopy Class vs Fundamental Group.

    They seem the same to me. So I can have many paths between a and b that are continuously deformable into each other while keeping the endpoints fixed. We say these function form a equivalence class [f]. This should be regardless if the endpoints are the same or not. The fundamental group seems...
  45. Useful nucleus

    Textbook problems in my class .... to cite or not to cite

    This is my first time to be an instructor for a class and I have to prepare problem sets for my students. For that purpose, I collect problems from different textbooks. Unfortunately, if I cite the source of each problem, students always find the solution manual of this textbook online and...
  46. FallenApple

    Why use an abstract class in object-oriented programming?

    So what is the purpose of an Abstract Class? Can I not get the same things by doing subclasses? For example. I can create a class called Vector_Space and then a subclass called Euclidean_Space We all know that Euclidean space is just a particular type of vector space. So I can just write the...
  47. T

    Programs What typically is considered an in-major class for a physics major?

    I was just wondering what typically is considered an in major class for a physics major? Is it only classes designated as PHYS? Or do math and chemistry classes also count? I can't seem to find a list of in major classes for physics majors on my universities website. Thanks.
  48. CivilSigma

    Studying Dealing with Unreasonable Note Sharing Requests in Class

    I have developed a pet peeve relating to un-reasonable note sharing requests from class mates and I don't know how to handle the problem of saying 'No' or about handling the situation. By un-reasonable , it means a friend asking for 5 lectures worth of notes, not 1 or 2 and for no apparent...
  49. W

    A Testing Fit in Latent Class Analysis

    Hi All, I am trying to wrap my brain around Latent Class Analysis (LCA). In the mean time, does anyone know how to test for goodness of fit and whether a given number of classes is somehow optimal? AFAIK, Log-Likelihood should decrease as a measure of improved fit when adding latent classes...
  50. N

    Help -- Summer school physics class

    I'm a substitute teacher with one year of classroom experience under my belt. I have just been hired to teach a summer school physics class. The class is 4 weeks long. The regular physics teacher taught this course a few years ago and has some powerpoints, lessons, documents, etc. but they are...
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