why the equation for kinetic energy is E=1/2 MV2 and the equation for
einstain equation is E=MC2..it does not have 1/2
2006-08-10 01:44:27 · 7 answers · asked by pouli 2 in Science & Mathematics ➔ Physics
kinetic energy is only valid up to a certain speed. when you go past that speed, none of ur high school forumlaes work and u have to learn quantum physics. btw, einstein's formulaes usually pertain to small particles as oppose to larger objects.
2006-08-10 01:50:52 · answer #1 · answered by Ak2ng 3 · 0⤊ 1⤋
Kinetic energy is defined the way it is so that the amount of work spent to accelerate an object is identical to the object's gain in energy, which is necessary for energy to be conserved.
Suppose you propel an object of mass one kilogram by a force of one Newton over a distance of one meter. This amounts to a work of one joule. According to Newton's second law, the object will be accelerated by 1ms^(-2), and this acceleration will last for sqrt(2) seconds due to the equation
distance = 1/2 time^2 * acceleration.
So the object will gain a velocity of sqrt(2) meter per second.
Now the m*v^2 of the object becomes
(sqrt(2))^2=2 Joule
so in order to have conservation of energy we need to define the kinetic energy as
1/2 m v^2
As for E=mC^2 I don't know, I find relativity theory hard to understand.
2006-08-10 09:48:47 · answer #2 · answered by helene_thygesen 4 · 0⤊ 1⤋
Kinetic energy: energy due to motion
Einstein's mass-energy equation: rest energy of a particle, meaning the energy contained by the particle just by existing. Object is not moving.
The mass-energy equation is simply part of the total energy equation that also involves kinetic energy, but in a relativistically "corrected" form. Basically for an oject in motion and not in the presence of any energy field.
total energy = rest energy + kinetic energy
The Newtonian (i.e. regular) equation of the kinetic energy is an approximation of the reltivistic kinetic energy.
2006-08-10 14:12:14 · answer #3 · answered by dennis_d_wurm 4 · 0⤊ 1⤋
einstein equation not for kinetic energy but rest mas energy of the particle that is energy equivalent to mass m, kinetic energy equation is energy of mass m when its moves with velocity v, i.e. energy by virtue of velocity
2006-08-10 09:10:12 · answer #4 · answered by Sanjay C 2 · 0⤊ 0⤋
einstein's equation is a relationship between mass and energy. it uses C (the constant of the speed of light) as a measuring point. it does not need any other numbers.
2006-08-10 08:50:03 · answer #5 · answered by John S 2 · 0⤊ 1⤋
It is because of the strange way time and distance and mass change with speed. See the source below for more complete information, but it is not simple.
2006-08-10 08:52:34 · answer #6 · answered by campbelp2002 7 · 1⤊ 0⤋
kinetic energy is energy by virtue of motion and einstein's energy is the energy obtained by converting mass
2006-08-10 08:49:57 · answer #7 · answered by raj 7 · 0⤊ 1⤋