Types of kinetic energy and whether random KE equals the sum of three types

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csharsha
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I was wondering about the types of kinetic energies that exist. Is it true that there are 3 types - vibrational, translational and rotational?

If so what is random kinetic energy?

Is random KE = vibrational + translational + rotational ?

Thanks !
 
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At first there is only normal kinetic energy of a single particle.

If you prefer you can work with center of mass of objects. Then you'd substitute the above with (center of mass translational energy)+(rotational energy about center of mass)
You can treat everything having these two types of energies only.

From here you can start defining whatever you like. It's just a matter of defining words.

Random kinetic energy is what people relate to heat. I'm not sure what a well-posed definition would be, but you surely can't find it in undergrad physics book, because there it's only vague concepts. Hmm, seems like a good question.
 
welcome to pf!

hi csharsha! welcome to pf! :smile:

i think i'd say that vibrational means regular …

so if you hit a bell it'll have vibrational KE, but even when it's "resting", there'll still be a tiny amount of random KE, ie heat

(and gases usually have only random KE, unless they're in a musical instrument)