determine the energy required to give an electron a speed of 0.90 that of light, starting from rest
Answers
Answer:
Total Energy and Rest Energy
The first postulate of relativity states that the laws of physics are the same in all inertial frames. Einstein showed that the law of conservation of energy is valid relativistically, if we define energy to include a relativistic factor.
TOTAL ENERGY
Total energy E is defined to be E = γmc2, where m is mass, c is the speed of light,
γ
=
1
√
1
−
v
2
c
2
and v is the velocity of the mass relative to an observer. There are many aspects of the total energy E that we will discuss—among them are how kinetic and potential energies are included in E, and how E is related to relativistic momentum. But first, note that at rest, total energy is not zero. Rather, when v = 0, we have γ = 1, and an object has rest energy.
REST ENERGY
Rest energy is E0 = mc2.