In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a chemical formula. The informal use of the term formula in science refers to the general construct of a relationship between given quantities.
The plural of formula can be either formulas (from the most common English plural noun form) or, under the influence of scientific Latin, formulae (from the original Latin).In mathematics, a formula generally refers to an identity which equates one mathematical expression to another, with the most important ones being mathematical theorems. Syntactically, a formula(often referred to as a well-formed formula) is an entity which is constructed using the symbols and formation rules of a given logical language. For example, determining the volume of a sphere requires a significant amount of integral calculus or its geometrical analogue, the method of exhaustion. However, having done this once in terms of some parameter (the radius for example), mathematicians have produced a formula to describe the volume of a sphere in terms of its radius:
V
=
4
3
π
r
3
{\displaystyle V={\frac {4}{3}}\pi r^{3}}
.Having obtained this result, the volume of any sphere can be computed as long as its radius is known. Here, notice that the volume V and the radius r are expressed as single letters instead of words or phrases. This convention, while less important in a relatively simple formula, means that mathematicians can more quickly manipulate formulas which are larger and more complex. Mathematical formulas are often algebraic, analytical or in closed form.In modern chemistry, a chemical formula is a way of expressing information about the proportions of atoms that constitute a particular chemical compound, using a single line of chemical element symbols, numbers, and sometimes other symbols, such as parentheses, brackets, and plus (+) and minus (−) signs. For example, H2O is the chemical formula for water, specifying that each molecule consists of two hydrogen (H) atoms and one oxygen (O) atom. Similarly, O−3 denotes an ozone molecule consisting of three oxygen atoms and a net negative charge.
In a general context, formulas are a manifestation of mathematical model to real world phenomena, and as such can be used to provide solution (or approximated solution) to real world problems, with some being more general than others. For example, the formula
F = mais an expression of Newton's second law, and is applicable to a wide range of physical situations. Other formulas, such as the use of the equation of a sine curve to model the movement of the tides in a bay, may be created to solve a particular problem. In all cases, however, formulas form the basis for calculations.
Expressions are distinct from formulas in that they cannot contain an equals sign (=). Expressions can be liken to phrases the same way formulas can be liken to grammatical sentences.
Homework Statement
in the old thread , i was told that
The formula for calculating the shear stress is a beam is ##τ = \frac{V ⋅ Q}{I ⋅ t}##
τ - shear stress
V - shear force
Q - first moment of area above the location where the shear stress is calculated.
I - second moment of area for the...
Guys...need a little help
Given
Internal fluid Pressure P (Not Pressure Drop)
flow rate Q
Length
Assume all the required parameters like viscosity, fluid density, temperature of the fluid, surface roughness and all losses (both major and minor) etc...
I need to find the internal diameter of...
Hello, I'm a mechanical engineering student and I'm working in traction control for Formula 1 cars.
The traction control in the cars is simple, too simple: an engine cut is done when the engine is at a certain RPM and slip value. A matrix of four values of RPM and slip has to be provided to...
In this video:
The professor at the end (at about 7:28), used the formula for scale factor and redshift as a(t) = 1/z, instead of the actual one a(t) = 1/1+z. And when we apply both of them, they give very different results. So, how could the professor use the first formula, which we were...
Homework Statement
Part (b)
Homework Equations
Vieta's formula
The Attempt at a Solution
Part (a):
I'm kinda stuck on part (b) - I tried multiplying the product of roots and got b^2 d^2, but I have no idea on dealing with the sum of roots.
The position vector of the center of mass of a triangle is ##\frac{1}{3}(\mathbf{a}+\mathbf{b}+\mathbf{c})##.
Is the position vector of the center of mass of a planar four-sided figure ABCD ##\frac{1}{4}(\mathbf{a}+\mathbf{b}+\mathbf{c}+\mathbf{d})##? Does this generalise to n-sided figure...
I am in search for journal articles/papers regarding the use of chromoly (41xx) or HSS tubes in racing car chassis (space-frame) for a literature review.
I wasn't able to find any papers up till now. Any help is greatly appreciated.
Hi,
If I want my spacecraft to accelerate at a rate that produces 1 G for a set distance (half way to another solar system) then decelerate at the same rate for the second half of the trip, what formula would I use? I would like to calculate the peak speed of the ship and the time dilation...
I need help in calculating the magnetic field outside of an iron core solenoid at different distances.
I have made an electromagnet by taking a 99.99% pure iron (5cm in length and 1 mm in radius) and wrapping wire over it. I have measured it's magnetic field at the end and cannot find an...
Hello!
Let's consider again a system of atoms with only two permitted energy levels E_1 and E_2 > E_1. When electrons decay from E_2 level to E_1, they generate a photon of energy E_{21} = E_2 - E_1 = h \nu. The number of photons (per unit frequency, per unit volume) emitted by such a system in...
Homework Statement
integral of cot^2 x / csc^8 x dx
Homework Equations
u = cot x
du = csc^2 x du
The Attempt at a Solution
if I use reduction formula I could answer this but it's going to be very very LONG SOLUTION
I just need some basic integral work.
Homework Statement
Refer to the second photo , Q= Ay
Does the author mean point P is at the center of the region (62.5mm x 100mm) ?The figure is not labelled well i am confused
Homework EquationsThe Attempt at a Solution
In the notes , I was told that y is the location of the shear stress is...
Homework Statement
Homework EquationsThe Attempt at a Solution
Firstly I tried to find the empirical formula:
C : H : O
65.2 : 8.75 : 26.05 (mass)
5.43 : 8.75 : 1.628 (mol)
3.34 : 5.37 : 1
10 : 16 : 3
C10H16O3
This gives a molecular mass of 184.
Now with the structure: It has to...
Hello, I'm currently writing a report on young's double slit experiment, and I've used the equation nλ/d = x/L and I was wondering if someone could explain the question? I know how it works, and how to solve for lambda, but could I have some more detail into why it works?
For example, why can...
Homework Statement
(b) Rationalize the numerator of your formula in (a) to rewrite the expression so that it looks like f(h)/g(h), subject to these two conditions: (1) the numerator f(h)defines a line of slope -1, (2) the function f(h)/g(h) is defined for h=0. When you do this
Homework...
The problem is to find the general term ##a_n## (not the partial sum) of the infinite series with a starting point n=1
$$a_n = \frac {8} {1^2 + 1} + \frac {1} {2^2 + 1} + \frac {8} {3^2 + 1} + \frac {1} {4^2 + 1} + \text {...}$$
The denominator is easy, just ##n^2 + 1## but I can't think of...
I've read the derivation of Kirchhoff's formula for three dimensional wave equation using the Euler-Poisson-Darboux equation. The derivation seems to be fine, but I thought that the Kirchhoff's formula as a final result is a kind of result that you should be able to verify it by substituting it...
The derivative for the parametric equations ##x=f(t)## and ##y=g(t)## is given by
##\frac{dy}{dx}=\frac{\Big(\frac{dy}{dt}\Big)}{\Big(\frac{dx}{dt}\Big)}##
The proof of the above formula requires that ##y## be a function of ##x##, as seen in...
Homework Statement
// given in JavaScript
var amount = parseInt($('input[name="amount"]').val());
var downpayment = parseInt($('input[name="downpayment"]').val());
var interest = parseInt($('input[name="interest"]').val());
var months = parseInt($("#months").val());Homework Equations
What is...
Homework Statement
Statement:[/B] Let y = u(x)v(x).
a) Find y' , y'', and y'''
b) The general formula for yn, the n-th derivative, is called Leibniz’ formula: it uses the same coefficients as the binomial theorem , and looks like https://i.gyazo.com/53728964c6b3ef142fd70f600c29e037.png
Use...
Consider a surface defined by the equation ##g(x, y, z)=0##. The intersection between this surface and the plane ##z=c## produces a curve that can be plotted on an x-y plane. Find the gradient of this curve.
By chain rule,
##\frac{\partial y}{\partial x}=\frac{\partial y}{\partial...
I am calculating damage per second (DPS) for a character in a video game.
This character strikes twice every 4th attack. (Doublestrike)
This extra strike does 50% of your attack damage.
This extra strike, along with all other strikes, can crit, meaning meaning they do twice the damage. My...
Homework Statement
from the notes , the author stated that force has the formula of ρ(L^2)(v^2) and also = ρ(L^3)
i think there's something wrong with the ρ(L^3)
Homework EquationsThe Attempt at a Solution
IMO , ρ(L^2)(v^2) can also be written as ρ(L^4)(T^2) , so Force is proportional to...
Homework Statement
part c
Homework Equations
The Attempt at a Solution
Jm+2=m+2-1/m+2 Jm=m+1/m+2 Jm
hence Jm+2<Jm
should i expend Jm+2 Jm+1 Jm to the term J0 then compare them?
why the inequality is <= but not <?
should i use M.I to proof it??[/B]
hi. i want to know how much force acts on every piston in an v8 engine and how much torque acts on the crankshaft . pls also tell me how much energy is created in an engine and how much of it is lost, say in friction and other factors. pls tell the force at start of engine in car and at...
Are there any equations out there which can calculate the heat dissipation of a water-cooled radiator with a fan on it? I would assume some of the variables would include:
-Volume of the radiator (240 x 199 x 45mm)=2149200mm^3
-Specific heat of water (4.187 kJ/kgK)
-Specific heat of the copper...
I need help making sure I am doing this right...
I am trying to solve for the total Lifetime Value of a member where I deduct their initial order from the total.
Variables:
A = # of members
B = 42% retention rate
C = \$750 lifetime spend
D = \$48 initial order
Total Lifetime Value = ABC -...
for my physics class a was working on a formula about conservation of energy
could you guys tell me if it is somewhat right and stuff i forgot about
=constant/s
so this is my try making a formula about the total energy in the universe
Hello all,
First of all I want to let you know that my question is very basic and that it involves discrete changes in velocity due to acceleration for every given Δt. I was trying to derive the relationship between the distance and acceleration in a formula and here's what I came up with:
1...
Revolutions(RPM) * Pi/30 = Angular velocity
What is the purpose of pi/30 in the equation. Why can we not just use rpm as unit of measure of angular velocity?
Hi I am having trouble with the derivation of the Rayleigh-Jeans from the steps shown at the hyperphysics web site. I have emailed Dr. Rod Nave who is listed as the person-in-charge at the site but I have been able to get a reply. It would really be much appreciated if anyone can have a look at...
Hi. I would like to ask a simple question. Here is the link of the file I study on. Immediately before the formula 4.9 for Biot number. Lc=V/As but I cannot understand it and I think it is not clear enough. How it appears, for what the word "characteristic" stands for, for example a pipe? For...
Hi All,
Regarding the Euler's formula Vertices - Edges + Faces = constant, for planar graphs what is the most frequent number? 1 or 2?
I understand that it is 2 when the outer region is included in the count.
Best wishes,
DaTario
Homework Statement
A model boat 1/100 size of its prototype has 0.12N of resistance when stimulating a speed of 5m/s of the prototype , what is the corresponding resistance in the prototype ? water is the fluid in both cases and frictional forces can be neglected.
Why the author need to...
I tried rearranging the formula multiple times but the answers I got made no sense.
The equation I have to use is a=(v2-v1)/t
I need to solve for v2
v1=1
a=2.27
t=3.88
If you cold help me rearrange the formula correctly that'd be great!
Thanks!
So I've been wondering if anyone knows a formula to relate these quantities in this scenario.
Say I have a container that originally has some volume, some amount of atoms at a constant velocity and is at a certain pressure and is airtight and then connect it to another container that has twice...
Homework Statement
[/B]
In a set of axes where the z axis is the axis of rotation of a finite rotation, the rotation matrix is given by
## \left[ \begin{array}{lcr} &\cos\phi \ \ \ &\sin\phi \ \ \ &0 \\ & -\sin\phi \ \ \ &\cos\phi \ \ \ &0 \\ &0 \ \ \ &0 \ \ \ &1 \end{array} \right]##...
I am working on a simple space game, and I am having trouble figuring out how to do collisions correctly; things bounce in the wrong direction or just get stuck together. Here are the things that are given:
Direction of objects A + B in degrees
Speed of objects A + B in meters per second
Mass...
Hello,
We have a pressurized Water-jet stream, where the nozzle d= 0.8 mm. We can measure the fluid output in mm3/s, to determine the speed by dividing over the area.
For this, F=ρAv2
However, the variable that would be changing, would be the distance from the nozzle to the target. If we...
I'm a bit stuck on this question (which is homework so hints are more welcome than outright answers). The question is:
A very long wire carrying a current I is moving with speed v towards a small circular wire loop of radius r. The long wire is in the plane of the loop and is too long to be...
Hello all,
I have a question, probably a controversial one:
is there any difference between the Formula- P= V*I and P= I*V?
is there any technical difference between the two expressions?
thank you.
Hi,
Can someone please decipher the following "beautiful" formula for me?
http://mathworld.wolfram.com/ReciprocalMultifactorialConstant.htmlm(19)=1/19!+?+?+...
* What is the next/previous addend in the series sum?
Thanks in advance.
I want to know how mathematician got the idea of external division , how they can say that a point can divide a line externally, what's the reason behind this discovery . Why they discovered it.
Homework Statement
Homework Equations
I want to say I should be using this one:
aA = aB + α x rA/B + ω x (ω x rA/B)
The Attempt at a Solution
The only problem is that if I'm supposed to find the angular acceleration then i'd have to take the... inverse of the cross product? To get it back...
Homework Statement
Use Cauchy’s integral formula to evaluate the integral along γ(t) of (z/(z+9)^2)dz
where γ(t) = 2i + 4e^it , 0 ≤ t ≤ 2π.
Homework Equations
Cauchy's integral formula
The Attempt at a Solution
I was just wondering is the integral not just zero by Cauchy's theorem since...
A few months ago I posted a simple equation that shows an interesting nexus between the difference between the squares of successive integers and the sums of their roots, viz:
Where y = x+1 then (x + y) = (y2 - x2)
Recently I expanded this relationship as follows:
Where n is any integer and y...
Homework Statement
I understand how to find the resonant frequency of a closed pipe but when the thickness of the walls varies, the resonant frequency varies. Is there a formula that i can use to find the resonant frequency of a closed pipe given the length, temperature, speed of sound and...