Formulas Definition and 545 Threads

  1. K

    Rearranging formulas. Accelerations

    If I were to solve for Aav Δd = viΔt+1/2aavΔt^2 Vi- initial velocity Aav is average acceleration
  2. E

    Taylor series for getting different formulas

    I am trying to establish why, I'm assuming one uses taylor series, \frac{\partial u}{\partial t}(t+k/2, x)= (u(t+k,x)-u(t,x))/k + O(k^2) I have tried every possible combination of adding/subtracting taylor series, but either I can not get it exactly or my O(k^2) term doesn't work out (it's...
  3. W

    Difference between These Electric Field Formulas

    just a quick question. I seem to have come across two very similar formulas for electric fields produced by uniformly charged parallel plates. My book gives the formula as E = \frac{\omega}{\epsilon_0} on the other hand the notes from my prof tell me that E = \frac{\omega}{2\epsilon_0}...
  4. micromass

    Schaum's Outline of Mathematical Handbook of Formulas and Tables

    Author: Seymour Lipschutz, Murray Spiegel, John Liu Title: Schaum's Outline of Mathematical Handbook of Formulas and Tables Amazon Link: https://www.amazon.com/dp/0071795375/?tag=pfamazon01-20 Prerequisities: None Table of Contents: Formulas Elementary Constants, Products, Formulas...
  5. J

    Prove these formulas for the distance between and a line/plane.

    I have two problems that are very similar. Problem 1: Prove that in the case where the line (L) is in ℝ2 and its equation has the general form ax+by=c, the distance from point B=(x_0{},y_0{}) to the line d(B,L) is given by the first formula. Problem 2: Prove that, in general, the distance...
  6. T

    Using Formulas in Sentences for Physics Paper

    I am translating a paper about a general physics question. I am not very familiar with physics other than the historical perspective and I am requesting some help with the grammar. I have a sentence that translates perfectly from the original Spanish as follows: “At the moment of t1 at...
  7. A

    How are formulas with inductive proofs discovered?

    There are certain formulas for which only inductive proofs are known. But since we need to know the formula first to prove it using mathematical induction, how do they get the formula in the first place? Here is an example: - Euler's formula in graph theory states that v-e+f=2 for all planar...
  8. G

    Memorising formulas or deriving them?

    Hello, I'm new here and this is the first thing I ever write on this forum, hence the question if this is the wrong place to post anything remains unanswered on my part. I came across this forum doing something on the internet, I can't remember what. I'm certain though that it was related...
  9. X

    Proving equivalence of two sinusoidal formulas

    Homework Statement While doing a physics assignment today, I came up with an expression in my answer that appears to be equivalent to sin(θ), however, i couldn't find a way to manipulate the expression to prove that it was. Could anyone point me in the right direction as to a way that I could...
  10. P

    I have troubles relating the idea with the formulas

    I have a problem with physics when it comes to relating new ideas with new formulas. Like right now I'm learning about Solids and Fluids, and the problem i have now is remember what formulas to use when, what each of the parts of the formula mean, etc. Is there a site or a list of questions that...
  11. Gliese123

    Which mathematical formulas are used in the search for extraterrestrial planets?

    Hello there! I'm currently working on an essay regarding astrophysics. The level of this essay is of high school standards but I do like math and physics so advanced calculations doesn't frighten me. :redface: Anyway so the essay's is about the astrophysics behind our search for...
  12. N

    Using Finance Formulas to find the best value of houses

    Homework Statement House one is going for 250.000 in the suburb and has a new power plant being built and also has a decrease in crime. House two is also 250.000 in city has an increase crime rate but has a new school being built. What house will be the best value in a 10 year span if you buy...
  13. N

    Finance formulas to compare the best value of a house

    Homework Statement House one is going for say 350.000 and House two is going for 250.000, both have the same bed and bath. Yet i want to add variables for instance house one has a decline in crime rate variable also a newly build mall. House two has new schools and crime is on the rise. So my...
  14. C

    How to determine steel strength formulas

    not sure if I am in the right place or not but nevertheless need some help I am trying to figure the correct steel to use for sign support. I am trying to determine if a 5 x 5 inch with .25 wall is as strong or stronger than a 6 x inch tube with a 3/16 wall. Can't find any formulas to help...
  15. T

    Formulas for Transformer Calculations

    I am an EET student. The professor I have is not very thorough in his examples and if you can't keep up with him or have x-ray vision to see through him to the board while he is working the problems then you just don't get the information needed. That said, I am currently trying to do a take...
  16. R

    Please help with formulas for take home test due tomorrow.

    Homework Statement The test has two parts. In Part A, you predict the results and give qualitative reasoning and in Part B, you actually calculate the values and verify if your predictions and the calculations are in agreement, and then give correct physics reasoning. Consider three events...
  17. A

    Use power-reducing formulas to rewrite

    Homework Statement Use power-reducing formulas to rewrite 152sin^2 x cos^2 x Homework Equations sin^2θ= 1-cos2θ/ 2 and cos^2θ= 1+cos2θ/2 The Attempt at a Solution 152(1-cos2x/2)(1+cos2x/2), 152/4 (1^2 - cos^2 2x), 30(1-(1+cos4x/2), and I got 30-30+30cos4x/2 as the answer but the...
  18. rcgldr

    Formulas for constant power acceleration

    This isn't homework. A friend asked about this so I decided to work out the formulas, but wanted to know if this was already done by someone here (otherwise I'll do the math). p = power (constant) a = acceleration v = velocity x = position t = time f = force Assume an object is...
  19. L

    Integration by u substitution for inverse trig formulas

    Homework Statement You know the U substitution proofs for inverse trig functions that go like this: \int\frac{1}{a^{2}+x^{2}}dx \int\frac{a\frac{1}{a}}{a(1+\frac{x^2}{a^2})}dx let u = x/a du= dx/a ... \frac{1}{a}tan^{-1}(x/a)+cI have searched google and can't find any of these proofs for...
  20. Saladsamurai

    Short Beam Bending: Roark's Formulas For Stress and Strain

    Is anyone familiar with the Roark's text that can clarify some terms for me? I am trying to clarify what Roark is referring to in the above mentioned text in the section on short beams (in the 5th edition 7.10 and in the 7th edition 8.10). Throughout the text, he uses the terms "span" and...
  21. L

    Integration by parts: Reduction Formulas

    Homework Statement Are there any sample problems worked out for trig functions of higher powers which are integrated by reduction formula? Like cos^8 or cos^10 or even just cos^6 or maybe?
  22. D

    Solve Physics: Find m When f=mc^2

    if f=mc squared what is m=?
  23. Z

    Degree-Raising Formulas for Bernstein Polynomials

    Two part question... Homework Statement Question 1: Let v = (a, b, c)T be a column vector which represents a coordinate vector of a polynomial in P2 with respect to the Bernstein basis. Find the 4 × 3 matrix which transforms v to the standard basis of P3. (Hint: First transform v to...
  24. L

    Understanding Dimensional Analysis in Basic Linear Motion Formulas

    One thing I enjoy as a new physics student is using formulas. I have been playing with the fundamental formulas in terms of units rather than their names. That is instead of a=v/t m/s/s=(m/s)/s or v=at m/s=(m/s/s) x s m/s=m/s Simple maths yea, but when I am getting to the bigger...
  25. P

    Calculating Average Velocity from Position Vectors: A Short Guide

    Homework Statement Suppose that the position vector for a particle is given as a function of time by (t) = x(t) + y(t), with x(t) = at + b and y(t) = ct2 + d,where a = 1.70 m/s, b = 1.20 m, c = 0.122 m/s2, and d = 1.18 m. (a) Calculate the average velocity during the time interval from t =...
  26. K

    Very Stuck on Deriving Projectile Motion Formulas

    Very Stuck on Deriving Projectile Motion Formulas Hey, I need some help :( . I've got an exam next Thursday, and I really suck at this stuff right now. So I need to get better! We are studying kinematics (1d and 2d). In this problem I need help with, we are given the attached diagram...
  27. F

    Looking for generalized formulas for Galilean transformations

    Dear Forum, I am familiar with the formulas between inertial frames of reference that move at a constant speed between each other. The observed object move at a constant speed or at a constant acceleration. It can be shown that while the positions and velocities are different in the two...
  28. X

    How to prove Satisfiability of boolean formulas is NP-complete

    How to prove "Satisfiability of boolean formulas is NP-complete" I can not figure out how to prove this. I have been trying to find something that explains it step by step, possibly even with an example. I can not find anything. Can somebody perhaps explain how you prove it or show me where I...
  29. T

    Testing Trig formulas for the math gre subject test

    Are you expected to know all of the trig formulas for the math gre subject test? I don't mean the easy ones, i mean ones such as the sum-to-product or product-to-sum. thanks!
  30. N

    Different formulas, same physics?

    Hello, Simple but perhaps odd question. e^{i(kx+\omega t)} and e^{i(-kx-\omega t)} The first formula describes a wave (with wavevector k and angular frequency omega) traveling to the left. And the second formula? I thought that it physically describes exactly the same situation...
  31. Femme_physics

    Does PNP transistor share the same formulas as an NPN transistor?

    The formulas in question are: Beta = Ic/Ib Ie = Ib ( 1 + beta ) Ie = Ib + Ic
  32. S

    A simple derivation of cosmological formulas

    Hello. I just added to my site a simple reasoning that quickly justifies the basic formulas of cosmology in General Relativity (Friedmann differential equations, assuming homogeneity and so on, including the role of the cosmological constant), without any heavy formalism (only assuming basic...
  33. B

    Predicate logic to prove equality of two formulas

    Hi All, I'm trying to write a program that will prove that a certain mathematical formula that is entered by a student is the same as the goal formula that I want. For example, if the goal formula is: 2 * X + Y then any of this student's answer can be considered correct: -> X + X + Y...
  34. K

    Accurate Formulas on Thermal Expansion

    1.Homework Statement . Can someone give me more accurate mathematical models on thermal expansion? for example, linear expansion. 2.Relevant equations L=L0(1+α∆T) this equation is not accurate. for example. When an object 100m long at 0oC (example: aluminum, α=2.4x10-5) is heated to...
  35. S

    Proper time and formulas without numbers?

    Proper time and formulas without numbers? (a) Write down the definition of proper time and explain how to use the appropriate formula with an example. (b) Write down the definition of proper length and explain how to use the appropriate formula with an example. (c) At what relative speed...
  36. R

    Formulas for designing an induction generator

    Hello. I am attempting to design a generator that works with the (admittitedly) inefficent design or rotating a conductive material inside a magnetic field to produce current flow. I could use help finding the formulas I need to calculate the amount of spin and size of coils i will need to...
  37. K

    Energy Formulas with the form (1/2)ab^2

    Homework Statement Can anybody help me think of Energy formulas/equations in the form below? Any form of Energy. (Please also state what does each variable stands for.) Homework Equations E = \frac{1}{2}ab2 = \frac{1}{2}ac Where c = ab The Attempt at a Solution So far, this...
  38. F

    Why Is My Attenuator Resistor Value Negative?

    Hello, I am trying to work out the resistor values for an 'O' attenuator. I am using the attached formula to work out resistor 3's value. My values to insert into this formula are: Input impedance (Z1) = 50 Ohm Load impedance (Z2) = 600 Ohm a =1.995 However when I substitute these figures I am...
  39. E

    Dimension formulas for Lie algebras

    Hi. 1. Can anyone definitively tell me what the dimension formula for the classical Lie algebras? For example, I know for SO(2n) or D_n, the dimension formula is SO(N)--> (N*(N-1))/2 E.g. SO(8) is 8*7/2 = 28. Ok, so what about SU(N+1) i.e. A_n, SO(2n+1) i.e. B_N and Sp(n) i.e...
  40. I

    Find formulas for the entries of M^n

    Homework Statement Let M = \begin {bmatrix} 8 & -1 \\ 2 & 11 \\ \end{bmatrix} Find formulas for the entries of M^n, where n is a positive integer. Homework Equations N/A The Attempt at a Solution I honestly have no clue where to start. We recently covered diagonalization, but I...
  41. D

    Lunar Lander Formulas for Fuel / Masses

    Homework Statement I am currently working on a computer science program which calculates the landing of a craft on a given planet. The user will enter in various known variables. I need some direction on what formulas to use for my program. I am strong in computer science however I...
  42. A

    Boltzmann constant in formulas

    Hi, I see that Boltzmann constant comes in different forms like: k=8.62*10-5 eV/K and also k=1.38*10-23J/K. Which one should I use in , say formula for intrinsic carrier concentration ni = sqrt(Nc*Nv)*e-Eg(T)/2kT ?
  43. T

    Using Chebyshev and other inequality formulas (maybe even Central Limit Theorem)

    34. Turner's syndrome is a rare chromosomal disorder in which girls have only one X chromosome. It affects about 1 in 2000 girls in the United States. About 1 in 10 girls with Turner's syndrome also suffer from an abnormal narrowing of the aorta. a. In a group of 4000 girls, what is the...
  44. P

    Fortran Fortran: mistake in writting this formulas

    Do I made a mistake in writting this formulas. I don't see them. Tnx for your answer. V1=(Kps*(1-ra**2)*(1-cos(6.2831853*y(1))))/(6.2831853**2* (1+ra**2+2*ra* cos(6.2831853*y(1)/2))**2) V2=(Kps*ra*(1-ra**2)*(1-cos(6.2831853*y(1)))*...
  45. M

    Difference between power formulas

    Hey there, I'm very confused between the difference of these power formulas. P= VI P= (I^2)(R) P=(V^2)/(R) Why is it that I often get different answers with all of them? Don't they all equal power? What are the situations I can use each one in?
  46. I

    Trig Identity for Arctan(a/b) with Rational Values?

    Hey, I'm wondering if anyone knows of a trig identity for arct(a/b) where a and b are rationals.
  47. V

    Understanding Charge Distribution in Electrostatic Systems

    Homework Statement http://u.spig.in/forum/105320795.jpg Homework Equations general Electrostats formulas The Attempt at a SolutionI tried to solve the problem using Energy conservation ie., Change in PE = Work done. But that seem to yield wrong answer (1) while the correct answer is 2. I...
  48. P

    How Do You Derive Formulas from the Work-Kinetic Energy Theorem?

    Homework Statement We have Work=Kinetic Energy which is : ##A=E_k=Fd=\frac{1}{2}mv^2## Find formulas of : Force, distance, mass, velocity squared and velocityHomework Equations ##A=E_k=Fd=\frac{1}{2}mv^2##The Attempt at a Solution ##F=\frac{\frac{1}{2}mv^2}{d}## ##d=\frac{\frac{1}{2}mv^2}{F}##...
  49. L

    Reduction formulas for integral of sin and cos

    Integrate sin2(x)cos4(x)dx using reduction formulas? My book says integral sin2(x)cos4(x)dx= integral cos4(x)-integral cos6x dx Now the reduction formula for n=6 for integral cos6(x)dx= (1/6)cos5(x)sinx+(5/6) integral cos4(x)dx Here is the part I don't get: It then says ...
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