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Quarlep
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Lets think we have a sphere and it moves a constant veloctity v.So it will have a kinetic energy.Is this kinetic energy efectts spheres particle energy.(sphere made up but atoms)
Thanks
Thanks
Quarlep said:Is this kinetic energy efectts spheres particle energy.(sphere made up but atoms)
nasu said:Not in the common definition. The KE of a macroscopic object does not include the internal KE. Not that you cannot think about it this way, too.
Can you rephrase your question. I'm not sure what you are asking.Quarlep said:Lets think another way we have a object uniform density then this object moves.then the kinetic energy will be sum of the small mass of the sphere.then we get it what's wrong in this model
I don't see anything wrong with that model. (We are ignoring any molecular structure and internal energy, just treating it as a classical continuum.)Quarlep said:Lets suppose we have a sphere.Sphere has a uniform density.When v=0 the total energy of sphere will be U(lets describe it that way).Now If we move the object with speed v then total energy will be U+1/2Mv2.Now we can divide M small m's like M=m1+m2... so then total energy will described that way.Like 1/2m1v2+1/2m2v2...=1/2Mv2.Important think is uniform density.Whats wrong in this model ?
nasu was just pointing out that that would ignore the random thermal motion of the molecules. Which is often done.Quarlep said:I am not telling wrong but nasu says its not correct.So I am confused.
But if you treat the object as classical rigid body, ignoring any molecular-level structure and internal energy, you can divide it into pieces and add the KE of each piece to get the total macroscopic KE of the object.sophiecentaur said:You can't add up the particle KE to get the bulk KE
Well, it would give you an answer but what could you do with number you got? I can't think it would give you a measure of how much energy you might extract from the system, for instance. (Except, perhaps, for a hot cannonball hitting a bucket of water and producing loads of hot, fast moving droplets of water. ?)Doc Al said:But if you treat the object as classical rigid body, ignoring any molecular-level structure and internal energy, you can divide it into pieces and add the KE of each piece to get the total macroscopic KE of the object.
Yes, if you divide it into pieces, all moving with the same velocity, the total KE is the sum of the KE of the pieces. But this is quite trivial.Doc Al said:But if you treat the object as classical rigid body, ignoring any molecular-level structure and internal energy, you can divide it into pieces and add the KE of each piece to get the total macroscopic KE of the object.
It might be trivial, but it is essential to understand. And it doesn't just work for pure translation, where every piece has the same velocity (that would be quite trivial).nasu said:Yes, if you divide it into pieces, all moving with the same velocity, the total KE is the sum of the KE of the pieces. But this is quite trivial.
These pieces are not the atoms or molecules, as hinted in the OP.
I'm not sure what he's asking.nasu said:My understanding was that he asks how the macroscopic motion influences the KE of atoms. But I am not sure.
Sure. I assume you mean that you subdivide the sphere into pieces and calculate the kinetic energy of each piece and add them up. That will give you the total KE.Quarlep said:A sphere moves a constant velocity.This sphere has a volume.Each per volume in the sphere has a mass and If we calculate all this mass kinetic energy we get total kinetic energy of object post 7
What do you mean?Quarlep said:Can somebody tell me last decision of it ?
I'm not sure what your idea is. (Beyond what I've already stated.)Quarlep said:My idea is true isn't it (I mean this cause everybody says different things)
This ideaDoc Al said:Sure. I assume you mean that you subdivide the sphere into pieces and calculate the kinetic energy of each piece and add them up. That will give you the total KE.
Well, I certainly agree with that (since you are quoting me!).Quarlep said:This idea
Kinetic energy is the energy an object possesses due to its motion.
The kinetic energy of a sphere is calculated using the formula KE = (1/2)mv^2, where m is the mass of the sphere and v is its velocity.
The kinetic energy of a sphere is affected by its mass, velocity, and the direction of its motion.
Kinetic energy and potential energy are two forms of mechanical energy. Kinetic energy is the energy an object has due to its motion, while potential energy is the energy an object has due to its position or state.
Yes, kinetic energy can be converted into other forms of energy, such as heat or sound, through processes like friction or collisions.