Condition for a particle to move relativistically

[sajad099]

What is the condition required for a particle to move relativistically?

 

[aashay]

What do you mean by a condition?Do you want to know at what speed it should move to be termed as relativistic?

 

[sajad099]

I want to know what should be done to a particle so that its velocity is comparable to velocit of light(relativistic)

 

[aashay]

There is nothing specific or special that needs to be done.

 

[n1person]

If you are wondering at what scales "effects of relativity" (time dilation, length contraction) can be noticed it is entirely dependent on the sensitivity of the instrument. The effect generally can be expressed by the lorentz factor:

1/sqrt(1-v^2/c^2) = L

so when v is small, L ~ 1, so little effect can be observed, meanwhile if v=0.999999c, the effect is very large and noticeable "by the naked eye," however if you have some sort of sensitive instrument you might be able to notice effects at lower velocities.

 

[K^2]

In particle physics, a particle is said to be relativistic if it's kinetic energy is comparable to or is greater than its rest mass energy.

So if you consider something like a dentist X-Ray with a 10kV cathode ray tube, electrons in it pick up at most 10keV. Compared to electron rest energy of 511keV, it's not that high. So you wouldn't normally think of these as relativistic particles. Though, whether you'll actually use relativity to describe these will depend on precision you need.

 

[Ich]

In particle physics, a particle is said to be relativistic if it's kinetic energy is comparable to or is greater than its rest mass energy.

I'm used to this distinction:
KE>~1% E0: relativistic
KE~E0: highly relativistic
KE>>E0: ultrarelativistic