I cant help but notice that Ek = 1/2 MV2 looks a lot like E = MC2. Should I take it that at the speed of light that the energy of the object is only 1/2 kinetic? If so what is the other half? Does the object get hot or something?
2007-06-29 08:06:54 · 8 answers · asked by timssterling 4 in Science & Mathematics ➔ Physics
If you write E = mc^2 in terms of the "rest mass" m_0 and the speed v of an object, it becomes E = m_0c^2/(1-v^2/c^2)^(1/2). Then take the approximation when v << c and you get that the energy of an object E = m_0c^2+1/2 mv^2, so the connection between the two is that at low speed the total energy of a particle of mass m is the rest mass energy given by Einstein's formula, plus the classical kinetic energy. I think you're a bit misled by the form of both formulas being the product of mass and velocity squared, but since they both pertain to energy they both will have the same units dimensionally.
2007-06-29 08:25:35 · answer #1 · answered by pegminer 7 · 1⤊ 0⤋
The equation E = m*c^2 describes the total energy of a particle. This means it's the rest mass energy and the kinetic energy added together.
It full, the equation is:
E = m*c^2 = sqrt(p^2*c^2 + m0^2*c^4)
where p is the particle's momentum, m0 is its rest mass, and c is the speed of light.
The relativistic momentum is found using this equation:
p = m0*v / sqrt(1 - v^2/c^2)
where m0 is the particle's rest mass, v is its velocity, and c is the speed of light.
If a mass were traveling at the speed of light, the denominator of the momentum equation would be 0, so it would have infinite momentum and therefore infinite energy.
2007-06-29 15:20:54 · answer #2 · answered by lithiumdeuteride 7 · 2⤊ 0⤋
Tim, Ek signifies ONLY the energy in body due to it's motion...whereas in E=mc^2,,, m is the effective mass and it is concerned with the total amt. of energy in the body (considering mass and energy to be equivalent).....and remeber,,, no object can move with speed of light.....y r u equating these 2 equations together......think over it,,, it dusn't make sense,,, both these energies are different things and not equal !!
2007-06-29 15:17:12 · answer #3 · answered by Vaibhav 2 · 1⤊ 0⤋
There is a similarity but E = mc^2 is derived from looking at the propogation of electromagnetic energy. Einstein considered an electromagnetic wave bouncing around in a conductive cavity and looked the concervation of energy and momentum. He derived the now famous result. It was so remarkable at the time tht he spent several months after getting the result to re-prove it.
2007-06-29 15:13:25 · answer #4 · answered by nyphdinmd 7 · 1⤊ 0⤋
No, it does not work that way. Ek = 1/2 M V^2 is only for "slow" speeds, much less than the speed of light. For example, 1860 miles per second is slow compared to light speed.
2007-06-29 15:15:36 · answer #5 · answered by morningfoxnorth 6 · 0⤊ 1⤋
there is heat produced by motion at high speed if there is an atmosphere involved. but there is also compression of the matter that is directly relative to its velocity.
2007-06-29 15:13:49 · answer #6 · answered by james p 3 · 0⤊ 0⤋
i think that at c the object is at maximum energy, since matter is a form of energy
2007-06-29 15:14:28 · answer #7 · answered by goodtobehappy 4 · 0⤊ 1⤋
That's complete...the other one is just a half, it is obvious isn't it ?
2007-06-29 15:12:56 · answer #8 · answered by Anonymous · 0⤊ 1⤋