What Is Mass In Physics

How Much Do You Weigh On Other Planets

While a person’s mass doesn’t change elsewhere in the solar system, the acceleration due to gravity and weight varies dramatically. The calculation of gravity on other bodies, as on Earth, depends not just on mass but also on how far the “surface” is from the center of gravity. On Earth, for example, your weight is slightly lower on a mountain top than at sea level. The effect becomes even more dramatic for large bodies, such as Jupiter. While the gravity exerted by Jupiter due to its mass is 316 times greater than that of Earth, you wouldn’t weigh 316 times more because its “surface” is so far out from the center.

Other celestial bodies have different values of gravity than Earth does. To get your weight, simply multiply by the appropriate number. For example, a 150-pound person would weigh 396 pounds on Jupiter, or 2.64 times their weight on Earth.

The Role Of The Higgs Boson

We could stop here, because weve understood the origin of most of the visible mass in the universe. Einstein didnt know where the mass of macroscopic objects came from, but particle physics revealed this late in the 20th century.

There is, however, one more twist in the story. Perhaps the most amazing one. If Einstein had known about it, he would certainly have loved it.

It is the role of the Higgs boson in generating mass. The Higgs boson, which is the excitation of the Higgs field, is what provides mass at the fundamental level: it lends mass to the elementary particles.

The Higgs story began with a serious problem in particle physics. By the late 20th century it was evident that gauge symmetries, mentioned earlier, are fundamental laws and they forbid any mass of force carriers.

Yet in 1983 massive force carries, the W and Z bosons, were discovered by the Large Electron-Positron ).

This was a serious conundrum: one of the most fundamental laws of nature, gauge invariance was at stake. Giving up gauge invariance would have meant starting particle physics over from scratch.

Amazingly, smart theorists figured out a way to have their cake and eat it too! They introduced the Higgs mechanism, which allows us to preserve gauge symmetries at the fundamental level but break them such that in our particular universe massive W and Z particles are still possible.

Measuring Mass With A Balance

Read Also: Electron Geometry Vs Molecular Geometry

What Is The Unit Of Mass

There are various units for calculating mass, like, kilograms, grams, lbs, pounds, etc., but the SI unit of mass is “kilograms” or kg. Every unit of mass can be converted to other units by using a proper conversion formula without affecting the meaning and essence of the quantity to be measured.

Note: 1kg is equal to 2.20462 pounds.

Solving For Mass In Other Science Problems

Don’t Miss: Calculate Half Life Formula

The State Of Units For Electromagnetism At The End Of The 19th Century

During the second half of the 19th century, the was becoming widely accepted for scientific work, treating the as the fundamental unit of mass and the kilogram as a decimal multiple of the base unit formed by using a metric prefix. However, as the century drew to a close, there was widespread dissatisfaction with the units for electricity and magnetism in the CGS system. There were two obvious choices for absolute units. of electromagnetism: the system and the system. But the sizes of electric and magnetic units were not convenient in either of these systems for example, the ESU unit of , which was later named the , corresponds to about 9×1011 , while the EMU unit, which was later named the , corresponds to 109 ohm.

To circumvent this difficulty, a third set of units was introduced: the so-called . The practical units were obtained as decimal multiples of coherent CGS-EMU units, chosen so that the resulting magnitudes were convenient for practical use and so that the practical units were, as far as possible, coherent with each other. The practical units included such units as the , the , the , etc., which were later incorporated in the SI system and which are used to this day. The reason the metre and the kilogram were later chosen to be the base units of length and mass was that they are the only combination of reasonably sized decimal multiples or submultiples of the metre and the gram that can be made coherent with the volt, the ampere, etc.

Uses Of Archimedes Principle

Relative density for solids and liquids can also be determined with the help of Archimedes principle.

For solids :

Relative density =

Relative density =

Relative density of a solid can be measured by weighing it first in air and then when fully immersed in water.

Let weight of the body in air = W1

Weight of solid body in water = W2

Loss in weight = W1 – W2

For liquids :

To measure relative density of a liquid, choose a body which can be fully immersed in water as well as in the given liquid. The body is weighed first in air, then fully immersed in water and then fully immersed in that particular liquid.

Let the weight of a body in air = W

Weight of the body fully immersed in water = W

Weight of the body fully immersed in liquid = W

Then loss of weight in liquid = W – W

and loss of weight in water = W – W

Relative density of the liquid =

Archimedes principle is used to design :

• The ships and submarines.
• The hydrometers to find the densities of liquids.
• The lactometers to test the purity of milk.

Tale of densities and relative densities of some substances:

Don’t Miss: Geometry Dash Icon Hack

Importance Of Mass In Daily Life

The mass of objects is tremendously important in our daily lives.

• We work hard to reduce our mass when we are dieting. Less mass translates to less weight.
• Many manufacturers work to create less massive versions of items ranging from bicycles and running shoes to cars. When an object is less massive it has less inertia and is easier to move.
• Body mass index is a measure of body fat based on your weight in relation to your height. Fat is lighter than muscle, so a high BMI suggests that your body contains more fat and less muscle than it should.

Newtons Laws Of Motion

• Explain the difference between mass and weight
• Explain why falling objects on Earth are never truly in free fall
• Describe the concept of weightlessness

Mass and weight are often used interchangeably in everyday conversation. For example, our medical records often show our weight in kilograms but never in the correct units of newtons. In physics, however, there is an important distinction. Weight is the pull of Earth on an object. It depends on the distance from the center of Earth. Unlike weight, mass does not vary with location. The mass of an object is the same on Earth, in orbit, or on the surface of the Moon.

Read Also: Jonathan Tennant Child Of Rage

Why Is The Definition Of Mass And Matter Interlinked

In my textbook the definition of matter and mass are:

• Matter: Any thing that occupies space and has mass .

• Mass: The amount of matter contained in a body.

While defining “matter” we refer to “mass”, but the definition of “mass” refers back to “matter”.

So isn’t this wrong? What will be the right definitions?

• 4$\begingroup$Who says mass is “the amount of matter contained in a body”? Neither gravitational nor inertial mass are defined that way.$\endgroup$Jul 4, 2015 at 16:37
• 1Jul 4, 2015 at 18:09
• 2$\begingroup$”Matter” is an ill-defined concept. “Matter” is a loose word for “stuff,” and what’s that? Everything with mass? Good luck, then photons aren’t matter. You begin to see the problem here? “Matter” is just an intuitive concept with no objective meaning and not a quantity we can measure. We can measure proprieties of matter, but not “matter” itself, because “matter” isn’t a quality or quantity that can objectively be said to be measurable.$\endgroup$

The word “matter” needs to be used with a great deal of care. In science, the word has definitely passed its use-by date. Some problems with the precise usage of the word are listed on the Wikipedia page for Matter and I quote:

…As such, there is no single universally agreed scientific meaning of the word “matter”. Scientifically, the term “mass” is well-defined, but “matter” is not.

As user Ruslan reminded me about the notion of relativistic mass:

“The mass of a body is a measure of its energy-content”.

Solved Examples Mass Formula

Q1. An object accelerated at a constant 5 m/s2 under a force of 5 Newton. Calculate the mass of the object involved?

Answer: Acceleration of the object = 5 m/s2Force on the object = 5 newtonTherefore, one must apply the formula of mass here,

F = mam = 5/5 = 1

Hence, the weight of the object is 1 kg.

Q2. The mass of an object happens to be 1 kg. Furthermore, a force of 2 Newton is applied on it. Find out the magnitude an direction of the objects acceleration

Answer: Here, mass = 1 kgNet force = 2 NewtonAlso, a = F / m

Hence, the acceleration happens to be 2 m/s2.

Hence, the direction of the acceleration = the direction of the net force

Read Also: Grade 6 Fsa Warm Ups Answer Key

What Does A Coherent System Of Units Mean

The system of unit which has derived units obtained from the base units without any numerical factor other than 1 is the coherent system of unit. 1 Watt is an example of a coherent system of unit as it is a ratio of 1 Joule to 1 second.

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

Tachyonic Particles And Imaginary Mass

A tachyonic field, or simply tachyon, is a quantum field with an imaginary mass. Although tachyons are a purely hypothetical concept not generally believed to exist,fields with imaginary mass have come to play an important role in modern physics and are discussed in popular books on physics. Under no circumstances do any excitations ever propagate faster than light in such theoriesthe presence or absence of a tachyonic mass has no effect whatsoever on the maximum velocity of signals . While the field may have imaginary mass, any physical particles do not the “imaginary mass” shows that the system becomes unstable, and sheds the instability by undergoing a type of phase transition called tachyon condensation that results in symmetry breaking in current models of particle physics.

The term “tachyon” was coined by Gerald Feinberg in a 1967 paper, but it was soon realized that Feinberg’s model in fact did not allow for superluminal speeds. Instead, the imaginary mass creates an instability in the configuration:- any configuration in which one or more field excitations are tachyonic will spontaneously decay, and the resulting configuration contains no physical tachyons. This process is known as tachyon condensation. Well known examples include the condensation of the Higgs boson in particle physics, and ferromagnetism in condensed matter physics.

E

. }}}}}}}.}

Read Also: Geometry Dash Verify Hack

Finding Mass From Density And Volume

Difference Between Mass And Weight

People often get confused between mass and weight and they end up using these two terms interchangeably. However, mass and weight are two different terms and it is important to understand the difference between them. The difference between mass and weight is shown in the table given below.

Did you know that we have different weights on the earth, the moon, and in space? However, our mass is the same everywhere.

Now, let us look at some important facts related to mass:

• Mass only has magnitude, hence, it is a scalar quantity.
• Weight has both magnitude and direction it is a vector quantity.
• Mass can also be defined as “stored energy in particles.”
• Mass represents the total atoms or particles that it contains.

Recommended Reading: What Does Ml Stand For In Chemistry

Concept Of Inertial Mass

Antiquity, and Greek science in particular, had no conception of inertial mass. Even the idea of quantity of matter , the antecedent of inertial or dynamic mass, was foreign to the conceptual scheme of Aristotelian natural philosophy. Paradoxically, it was Neoplatonism and its admixtures of Judeo-Christian doctrines, with their emphasis on the spiritual and immaterial nature of reality, that laid the foundations for the inertial conception of mass, which later became the basic notion of materialistic or substantial philosophy. To accentuate the immaterial, sublime source of all force and life in the intellect or God, Neoplatonism degraded matter to impotence and endowed it with inertia in the sense of an absolute absence of spontaneous activity. For Plotinus, Proclus, Philo, Ibn Gabirol, and the Platonic patristic authors, matter was something base, inert, shapeless and “plump,” attributes that reappear in Kepler’s characterization of matter as that which is too “plump and clumsy to move itself from one place to another.”