Question about Rela+ KE calcs

[Armorchompy]

The Kinetic Energy has to say this about the subject: "The relativistic kinetic energy value is only accepted up to 4 times the Newtonian value: The kinetic energy value calculated using the formula for relativistic kinetic energy is only accepted to the point where it is 4 times as high as the value of Newtonian kinetic energy. That is the case, if the speed of the moving object is above 93% of the speed of light. For kinetic energy values above that, which are not faster than light, 4 times the kinetic energy value should be taken. Reason for this rule is that the relativistic kinetic energy diverges towards infinity for speeds approaching the speed of light. So to not get inflated extremely high results setting a threshold at 4 times the kinetic energy value was decided upon."

My problem is really simple, and it's that I have no clue what that means. Do i need to multiply the 93% c SoL result by 4? Or just use another formula altogether? I find the way this is worded incredibly confusing. Moral of the story is, say I have the speed and mass of this object, and the speed is, for example, 98% of the speed of light, how do I calculate that KE?

 

[Armorchompy]

Bump

 

[Ricsi-viragosi]

While I disagree that rule and I think its dumb to set a completely arbitrary number on it, it simply means that if you are calculating the kinetic energy of something being thrown/moving at Rel+ speeds, you *4 the result you get.

So, 0.5*(weight in kilograms)(speed in m/s)^2*4

 

[Armorchompy]

Wouldn't that just raise the result even further?

 

[Thelastmlg]

Why do that instead of relativistic kinectic energy.

 

[Ricsi-viragosi]

Wouldn't that just raise the result even further?

Yes. That is the point. Kinetic Energy dives immensely higher at relativistic speeds.

 

[Armorchompy]

Oh, I see.