Understanding Mass

Gerald Oct 2014

Newton’s law of Motion

Let us start with the Postulate

F = ma If a body has a acceleration it

needs a force and the relation to acceleration and force is F= Ma.

Is the Newton’s law Correct

How can you verify in this law ?

F = ma

Measuring The mass

We don’t know how to measure the mass.

we don’t know how to measure the force.

How are going to find the mass of anything?

One Kilogram Mass is Born

In 1799, a kilogram, was defined as mass equal to the mass of one cubic decimeter of distilled water at 4°C.

The material of the standard kilogram was a platinum cylinder.

The First General Conference of Weights and Measures held in 1889approved this new standard.

Hooks Law Extension “x”(m)

Acceleration, “a” (m/s2)

Force , “F”(kg m/s2)

0.1 -1 -1

0.2 -2 -2

0.3 -3 -3

-0.1 1 1

-0.2 2 2

-0.3 3 3

Mass = 1 kg here

Mass of Anything

You can attach a known mass to a spring, see what acceleration it produces.

Now attach a unknown mass to the same spring, you now know the mass of the Elephant by the acceleration it produces.

This way you can find the mass of anything.

Another Mass and Another Law

Another Mass and Another Law

•Here again we have more question than answers.

•As in laws of motion, what is measurable here?

Measuring the Value of “G”

Torsion balance

Mass of Earth Now you are in a position to find the mass of

earth, by shooting an object in stable circular orbit, you have all the values except the mass of earth and you compute it as follows.

 

G M1 M2/ r2 = M2V2/r

.i.e. equating GRAVITATIONAL FORCE and CENTRIPETAL FORCE.

By using the laboratory value for G allows us to deduce the mass of the Earth: 5.98 X 10 24 Kg.

Mystery of Many Masses

Inertial mass.

Active gravitational mass.

Passive gravitational mass.

Rest Mass

Relativistic Mass

Quantum Mass  

E=mc2 m=W/a

m=F/a

The Mystery of Two Masses.

Inertial mass - measures an object's resistance to being accelerated by a force.

Gravitational mass measures the gravitational force exerted and experienced by an object.

Although inertial and gravitational mass are conceptually distinct, experiments so far has demonstrated no difference between them.

What we do not know about mass

What we do not know about Mass ?

Why the values of Inertial Mass and Gravitational Mass is same up to 12th decimal measured so far?

At what decimal the Inertial Mass and Gravitational Mass will diverge?

Will it diverge at all?

A Glance at Particle Physics

More Adventure With Mass

We know our Universe is made of Hadrons and Leptons at the fundamental level

Hadrons forms matter and Leptons forms the force carriers.

Forces ..... Force CarriersStrong Nuclear Force ...... GluonWeak Nuclear Force ...... Z , W BosonElectromagnetic Force ...... Photon Gravitational Force ...... Graviton ?

What else we do not know?

Since we do not know about mass well enough; we do not know enough about Gravitational Force yet.

What carries the force of Gravitation? A hypothetical particle Graviton was

theorised to be the force carrier of Gravitational force.

Graviton has not yet been detected yet.

What else we do not know?

Einstein hypothesised that Gravitational

Force is carried by Gravitational Waves travelling at the speed of light.

Gravitational Wave also has not yet been detected.

What You Guys Can Do

Find answers to the one or more questions above about mass haunting the scientific community.

Did you realise, that Einstein worked hard fruitlessly during his last thirty years of his life to find answers to the questions we were contemplating today.

Use your first thirty years of your life to find answers to the questions Einstein could not find answers in his last thirty years of his life.

Thanks for Listening.

Questions ?

Exercise for those interested in mass Photon is known to be a mass less

particle.

We know momentum is m.v and KE is ½.m.v2

How does Photon has non zero momentum and energy?

References:

Articles from Wikipedia free encyclopedia.

The God Particle- Leon Lederman. Beyond God Particle - Leon Lederman Fundamentals of Physics I and II – Yale

University Open Course.