about E = mc2?

Question

my friend ask : if c tends to one then E= M then what is difference between mass and energy.

Answer 1

c doesn't change. You can pick units where c is defined as 1--then all other speeds are measured as fractions. In this case, mass and energy are measured in the same units. This is actually quite useful in accelerator physics or any other situation where the kinetic energies of the particles are comparable to the rest masses. In such situations energy and mass are much more readily interconvertible.

There is still a contextual difference between "mass energy" and "kinetic energy," in just the same way as there is a contextual difference between the kinetic energy in an oscillator and the potential energy in the same oscillator. It's that the same stuff (energy) is stored or expressed in different forms.

It's as with cash money versus "illiquid" assets. I have a gold ring worth $1,000. Do I have $1,000? No. But I could convert that ring to $1,000 and so my net worth includes that $1,000. But usually I list my possessions in the form in which they exist, rather than as equivalent dollar values.

Answer 2

C= speed of light
The relationship between mass (m) and E(energy)
can be examplified by this formulae:
F(force)=m(mass) X a (acceleration) or F=ma

If you want to experiment the relationship between energy(E) and mass(m)
Hold a ball in your hands. The ball has mass, right?
you are holding the ball, so the mass of the ball is at rest, its speed is 0 (for now) because you are holding it. But your ball has potential energy.
Now throw the ball againts a window. the ball is now heading for the window (it has a speed) the potential energy has become kinetic energy, because you threw thew ball and it went from 0 velocity to X velocity, or (a).

When the ball hits the surface of the glass (collision) it will either brake the glass or bounce on it. Depending on the mass of the ball multiplied by its speed and the mass of the window multiplied by its speed.

Obviously in this system the glass has a velocity of 0 because it is not moving, but it has a mass.
ie:
Ping pong ball againts a window
m1*v1=m2*v2
the ball will bounce because the mass of the ball combined with its speed has less energy than the mass of the window combined with its speed.

If you use a billiard and a thin glass the same formulae applies.
But the billiard ball has more mass than a ping pong ball. hence more energy...The glass will brake.

*** do not try this at home!

Answer 3

C is a constant, it's the speed of light in a vacuum and as such it never changes and definitely doesn't tend to one.

Mass is the amount of matter something contains and the more matter something contains, the more "massive" it is said to be. In simple terms, mass is similar to weight but the mass of an object never changes, the weight can change because this is a measure of how hard something is pushing down and this is affected by gravity for example.

Energy is a measure of being able to do work. There are many forms of energy, such as heat, mechanical, electrical, radiant, chemical, and nuclear energies.

In the equation E is the amount of energy in something, it is measured in Joules and is calculated by multiplying the mass (in kilograms) by the speed of light (299,792,458 meters per second) squared.

It shows us that even the tiniest of objects has a huge amount of energy. A single drop of water (mass 1 gram) contains the same amount of energy that an average human being would use if they lived for 25 million years (based on 10000 Joules / 2400 Kcalories a day).

Answer 4

According to Einstein, matter and energy are just different forms of the same thing. In Einsteins theory a mass cannot be accelerated to a speed greater than that of light, hence if a mass is traveling at the speed of light and energy is added it must be converted to mass, hence any mass can be converted to energy equal to that mass x velocity squared with Vc=1. this formulae shows a relationship of the quantities of mass and energy, A conversion factor.

This is actually a restatement of F=MV^2 with a special relativity to c to describe the equivalence of mass and energy.

Your friend has just had the same epiphany that Einstein did.

As the velocity tends to 1c!
It would seem that none of the answerers understood your question. I will clarify. M x .5c^2 = .25E... at 1c mass=energy
Soooo 1Mw of energy=1Mw of mass, yes according to Einstein mass can be measured in Watts.
c being the unit of measurement. as in the velocity tends to 1 mile/hr or 1km/hr... 1c!

Answer 5

C does NOT tend to 1 but you can choose your units so as to obatin c=1. In this case time and lenght would have the same unit of measure.

Anyway one of the consequence of Einstein Special Relativity is that mass and Energy are the same

Answer 6

C represents the speed of light. It is called C because it is the same value for all observers regardless of their motion. It is notated by the letter C because it is the universal Constant - it cannot "tends to one."

Mass and energy are interchangeable in as much as mass can be converted to energy and vice versa.

They are essentially the same thing, only in different form. A little like ice, steam and water - they, too, are essentially the same thing only in different forms.

Answer 7

No difference. Atomic bombs will be useless and the all the reactors will stop. Most of the life will cease not to exist due to starving for energy. Even sun and all the stars will go dark. The universe as we know it will ve gone in to very cold.

Answer 8

c is always the speed of light or 3 X 10^8 m/sec

It cannot tend to one.