What Does R Stand For In Physics

Watch The Video To Find Out What Base Measurements Are

Keep visiting BYJUS to get more such information. BYJUS also helps the students for their exams by providing sample papers, question papers and preparation tips.

Put your understanding of this concept to test by answering a few MCQs. Click Start Quiz to begin!

Select the correct answer and click on the Finish buttonCheck your score and answers at the end of the quiz

Limitations Of Ideal Gas Law

There is a reason it is called the ideal gas law instead of the actual gas law. The validity of the ideal gas equation depends on a handful of idealized assumptions about the character and behavior of gases. First, the ideal gas law assumes that particles in a gas obey Newtons laws of mechanics. This means that gas particles are assumed to obey the laws of force and gravity described by Isaac Newton and the effects of electrostatic intermolecular attractions are not considered.

Todays science fiction is tomorrows science fact. Isaac Asimov

Second, it is assumed that the molecules of the gas are negligibly small compared to the entire volume of the gas. This assumption allows scientists to simplify their calculations for the volume by leaving out the non-zero volume that molecules actually have.

Thirds, collisions between the molecules and the walls of the container are considered to be perfectly elasticthat is, no kinetic energy is lost from collisions. In actuality, a tiny amount of kinetic energy is absorbed by the walls of the container and is dissipated as heat. Normally, this tiny amount of energy is negligible and can be ignored.

What Is Velocity R

For vector calculus, we make the same definition. Definition: Velocity. Let r be a differentiable vector valued function representing the position vector of a particle at time t. Then the velocity vector is the derivative of the position vector. v=r=xi+yj+zk.For vector calculus, we make the same definition. Definition: Velocity. Let r be a differentiable vector valued functionvector valued functionA vector-valued function, also referred to as a vector function, is a mathematical function of one or more variables whose range is a set of multidimensional vectors or infinite-dimensional vectors.https://en.wikipedia.org wiki Vector-Vector-valued function Wikipedia representing the position vector of a particle at time t. Then the velocity vector is the derivative of the position vector. v=r=xi+yj+zk.

Don’t Miss: Multiple View Geometry In Computer Vision

What Is Ohms Law

Ohm’s Law is a formula used to calculate the relationship between voltage, current and resistance in an electrical circuit.

To students of electronics, Ohm’s Law is as fundamentally important as Einstein’s Relativity equation is to physicists.

E = I x R

When spelled out, it means voltage = current x resistance, or volts = amps x ohms, or V = A x .

Named for German physicist Georg Ohm , Ohm’s Law addresses the key quantities at work in circuits:

If two of these values are known, technicians can reconfigure Ohm’s Law to calculate the third. Just modify the pyramid as follows:

If you know voltage and current and want to know resistance , X-out the R in the pyramid and calculate the remaining equation .

Note: Resistance cannot be measured in an operating circuit, so Ohm’s Law is especially useful when it needs to be calculated. Rather than shutting off the circuit to measure resistance, a technician can determine R using the above variation of Ohm’s Law.

Now, if you know voltage and resistance and want to know current , X-out the I and calculate the remaining two symbols .

And if you know current and resistance and want to know voltage , multiply the bottom halves of the pyramid .

Example 1: Voltage and resistance are known.

Why $\vec$ Is Commonly Use For Vector Equation

I’m wondering why $\vec$ is commonly use in mathematics and physics for denote the vector equation.

Edit/Added clarification: I’m wondering why the letter $r$ is commonly use in mathematics and physics for denote the vector equation.

• $\begingroup$Vectors have a magnitude and a direction. The arrow helpfully reinforces the idea that $r$ is more than just a number but also has a direction.$\endgroup$Aug 15, 2013 at 13:55
• 2$\begingroup$Are you asking about the arrow or are you asking about the choice of letter $r$?$\endgroup$Aug 15, 2013 at 13:56
• 3$\begingroup$I conjecture that physicists often use $r$ for “radius vector”. But I have nothing to back that up.$\endgroup$Aug 15, 2013 at 14:05
• 2Aug 15, 2013 at 14:12
• 1$\begingroup$Though obviously false, the following explanation has been popular with my students: It is a verbal joke : since the vector gives your location from the origin, it tells you where you “are”.$\endgroup$

I have seen the letter $r$ used in physics to denote the position vector of a particle. It is also called the radius vector and may be that’s why $r$ is more commonly used. In math, when the variable $r$ is used, it’s not really for any particular reason. Also I haven’t seen $\mathbf$ or $\vec$ used in pure math .

The use of the variable $r$ to denote a vector is arbitrary.

If you’re asking why people use the letter “r” , I don’t know why. Personally, I use “$\mathbf x$” more than “$\mathbf r$”.

$$\vec\in\mathbb^d$$

Recommended Reading: Do You Know Your Geography Worksheet Answers

How Voltage Current And Resistance Relate

An electric circuit is formed when a conductive path is created toallow free electrons to continuously move. This continuous movement offree electrons through the conductors of a circuit is called a current, and it is often referred to in terms of “flow,” just like the flow of a liquid through a hollow pipe.

The force motivating electrons to “flow” in a circuit is called voltage.Voltage is a specific measure of potential energy that is alwaysrelative between two points. When we speak of a certain amount ofvoltage being present in a circuit, we are referring to the measurementof how much potential energy exists to move electrons from one particular point in that circuit to another particular point. Without reference to two particular points, the term “voltage” has no meaning.

Free electrons tend to move through conductors with some degree offriction, or opposition to motion. This opposition to motion is moreproperly called resistance. The amount of currentin a circuit depends on the amount of voltage available to motivate theelectrons, and also the amount of resistance in the circuit to opposeelectron flow. Just like voltage, resistance is a quantity relativebetween two points. For this reason, the quantities of voltage andresistance are often stated as being “between” or “across” two pointsin a circuit.

Let’s see how these equations might work to help us analyze simple circuits:

What is the amount of current in this circuit?

What Is Single Frequency In Physics

The only sound which consists of a single frequency is the pure SINE TONE such as produced by a sine wave OSCILLATOR or approximated by a tuning fork. All other sounds are complex, consisting of a number of frequencies of greater or lesser intensity. The frequency content of a sound is its SPECTRUM.

Also Check: Kuta Software Infinite Algebra 1 Writing Linear Equations

Deriving The Formula: V=wr

605

How to derive the formula:v=wrwhere v is the tangential velocity, w is the rotational velocity, and r i the radius vector?From the attached image, it can be concluded that : w=r x v, also v=w x r, and r= v x w. All three vectors are perpendicular to each other, therefore the intensity of each vector can be calculated by vector multiplication. Then :w=rv, v=wr, r=vw, this system of equations is true if w=v=r which mustn’t be true. I need an explanation. What did I wrong to arrive at this incorrect equality?

What Does R Stand For In This Physics Formula

W = F * delta r

Just curious what lower case r stands for?

Its beginning college physics to answer your question, I never took physics and high school. I dont care much for my professors teaching methods but that makes more sense so essentially all Im looking at is a simple formula to measure the work based off of force and distance. I think I got it thank you for your input.

Read Also: Can You Use Tan Physics On Your Face

What Does R Mean In Equations For Gravitational Force And Centripetal Force

On one hand, that’s easy for me to answer:

In the gravitational force equation F = GMm/r,2 the r represents the distance between the centers of the two objects. I often use the variable d to emphasize this meaning.

In the centripetal force equation F = mv2/r, the r represents the radius of the circular motion.

These facts are also easy for students to read and recall. It’s not as easy for students to put into practice. They see the letter r, hear “radius,” and plug in any random distance they can pluck out of the problem stem.

And, this < pop> pull-a-radius-value-out-of-their-tuckus method is very often successful in a gravitation problem. When an object is on the surface of a planet, the r value is in fact the planet’s radius. When a satellite undergoes a circular orbit around a central planet, the orbital radius r is in fact the same as the r distance between the satellite and the planet’s center.

So why does it matter if students truly understand the difference between these two meanings of r? In what possible physical situation in introductory physics does this difference even matter? Here’s one.

Two stars, each of equal mass M, maintain a constant distance x apart and rotate about a point midway between them at a rate of one revolution in every time t1.

Why dont the two stars crash into one another due to the gravitational force between them?

*In the Before Times, I’d clasp hands with a student and pull lightly.

The Basic Science Of Circuits

Circuits, like all matter, are made of atoms. Atoms consist of subatomic particles:

Atoms remain bound together by forces of attraction between an atom’s nucleus and electrons in its outer shell. When influenced by voltage, atoms in a circuit begin to reform and their components exert a potential of attraction known as a potential difference. Mutually attracted loose electrons move toward protons, creating a flow of electrons . Any material in the circuit that restricts this flow is considered resistance.

Reference: Digital Multimeter Principles by Glen A. Mazur, American Technical Publishers.

Recommended Reading: What Is Frame Of Reference In Physics

Physics Notation And Terminology

Hans Laue

The system of notation I am using in the applets in the contractwith Alberta Learning and in the text documents accompanying theapplets is unambiguous: different notation for different quantities.The system conforms with what you will find in general physics texts,with some minor differences.

One difference is that general physics texts often don’t have asymbol for “distance traveled”. They just don’t calculate thedistance traveled and therefore don’t need a symbol. Also, althoughbooks are coming out now with a vector notation thatuses letters in boldface with an arrow on top, many books still useonly boldface. My applets and text use boldface plus the arrow. Thereason the arrow is important, I think, is because that is whatstudents will use in their handwriting. Students have a greattendency to omit the arrow, and so we must model good practice forthem. Anyway, the arrow is used also in the Alberta Education manuals.So the arrow is not an issue. I just would like to point out that notall textbooks use arrows and that this is one difference between thenotation proposed here and that found in general physics texts.

Here is the system that I have used for years in first-yearuniversity teaching, both in instruction and in the present MAP andthe earlier CALiPH computer modules. I can recommend it.

Time instant: t

Time interval: Dt

Distance traveled: s

Straight-line distance between two points and magnitude of a displacement:d

Position vector:

or D

Speed: v

Symbols Used In Modern Physics

From the above text on physics symbols, we understand that in Physics, we use various symbols or notations to denote different quantities. The denotations make the representation of the quantities easier.

It was also interesting to see that some physics symbols were very relatable while some were unrelatable . Also, we noticed that a particular symbol was related to more than one quantity.

• CBSE Class 8 Notes

Read Also: What Is Radiation In Chemistry

Gas Constant In Chemistry

• In chemistry, the gas constant goes by many names, including the ideal gas constant and universal gas constant.
• It is the molar equivalent to the Boltzmann constant.
• The SI value of the gas constant is exactly 8.31446261815324 JK1mol1. Usually, the decimal is rounded to 8.314.

The Gas Constant is the physical constant in the equation for the Ideal Gas Law:

P is pressure, V is volume, n is the number of moles, and T is temperature. Rearranging the equation, you can solve for R:

R = PV/nT

The gas constant is also found in the Nernst equation relating the reduction potential of a half-cell to the standard electrode potential:

E is the cell potential, E0 is the standard cell potential, R is the gas constant, T is the temperature, n is the number of mole of electrons exchanged, F is Faraday’s constant, and Q is the reaction quotient.

The gas constant is equivalent to the Boltzmann constant, just expressed in units of energy per temperature per mole, while the Boltzmann constant is given in terms of energy per temperature per particle. From a physical standpoint, the gas constant is a proportionality constant that related the energy scale to the temperature scale for a mole of particles at a given temperature.

Units for the gas constant vary, depending on other units used in the equation.

What Is R In Physics Projectile Motion

Range of the Projectile, R: The range of the projectile is the displacement in the horizontal direction. There is no acceleration in this direction since gravity only acts vertically. shows the line of range. Like time of flight and maximum height, the range of the projectile is a function of initial speed.

Recommended Reading: How To Find Force In Physics

Value Of The Gas Constant

The value of the gas constant ‘R’ depends on the units used for pressure, volume and temperature. Prior to 2019, these were common values for the gas constant.

• R = 0.0821 liter·atm/mol·K
• R = 8.3145 J/mol·K
• R = 8.2057 m3·atm/mol·K
• R = 62.3637 L·Torr/mol·K or L·mmHg/mol·K

In 2019, the SI base units were redefined. Both Avogadro’s number and the Boltzmann constant were given exact numerical values. As a consequence, the gas constant also now has an exact value: 8.31446261815324 JK1mol1.

Because of the relatively recent definition change, use care when comparing calculations prior to 2019 because the values for R are slightly different before and after the redefinition.

Examples Of Physical Symbols

Also, the symbols used for physical quantities are vastly different. Sometimes, the symbol may be the first letter of the physical quantities they represent, like d, which stands for distance. Other times, they may be completely unrelated to the name of the physical quantities, such as c symbolises the speed of light. They may also be in the form of Greek characters, like , which stands for wavelength.

Below is an elaborated list of the most commonly used list of symbols in physics with their SI units. Please note that a particular symbol might relate to more than one quantity.

You May Like: What Is Erect In Physics

Is Resistivity A Constant

But resistivity is a constant. if you change the resistance and length of conductor and then experimentally measure the resistance, and put it in the formula, youll find that the resistivity has remained a constant for all different A and L, because R gets suitable modified to keep resistivity constant.

What Is The Difference Between R And R

Text Solution

Answer

Transcript

the given Krishna what is the difference between small R and capital r so you know that winnou net when the mass of the gain when Tamma ok today when the mass of the gas given in kg given in

kg then the universal gas constant is used is small R then the constant then constant used send constant used in smaller if Dama vitamin soft again speak the mass of the gas is given in given in mall

then the constant used in send constant Tuesday capital are ok and the both the constant are known as universal gas constant motor constant are known as universal gas constant using ideal gas equation ok so this is vaccination for this

thank you

Recommended Reading: How Biological Vectors Are Responsible For Malaria

What To Validate Using Ohms Law

Ohms Law can be used to validate the static values of circuit components, current levels, voltage supplies, and voltage drops. If, for example, a test instrument detects a higher than normal current measurement, it could mean that resistance has decreased or that voltage has increased, causing a high-voltage situation. This could indicate a supply or circuit issue.

In direct current circuits, a lower than normal current measurement could mean that the voltage has decreased, or circuit resistance has increased. Possible causes for increased resistance are poor or loose connections, corrosion and/or damaged components.

Loads within a circuit draw on electrical current. Loads can be any sort of component: small electrical devices, computers, household appliances or a large motor. Most of these components have a nameplate or informational sticker attached. These nameplates provide safety certification and multiple reference numbers.

Technicians refer to nameplates on components to learn standard voltage and current values. During testing, if technicians find that customary values do not register on their digital multimeters or clamp meters, they can use Ohm’s Law to detect what part of a circuit is faltering and from that determine where a problem may lie.