Does Heat Apply Force in Molecular Breakage?

[first martiAn]

When we heat something then it breaks and it is due to the transfer of energy . But what if we ignore the energy and thought it as Force I.e. the object molecules break due to Force applied on each other ( molecules) . So is it right to say heat apply Force.?

 

[DrClaude]

Heat is simply the transfer of energy due to a difference in temperature. If something breaks because of heat, it can be because of a series of factors, such as thermal expansion, the softening of materials, the breaking of chemical bonds, etc. So no, heat is not a force.

 

[first martiAn]

what if we thinks of star's heat?? Is it not applying force on earth?

 

[jbriggs444]

what if we thinks of star's heat?? Is it not applying force on earth?

Knowing how much heat energy is in a star is not enough to tell us how much force its light applies on the earth.

 

[mishima]

I think what OP is really getting at is that temperature is related to the motion of atoms. In a solid, its mainly the vibrational motion as they stand in the lattice structure (ie the pattern of Si and O in quartz crystal). Where they stand in the lattice structure is determined by electrostatics. In other words, the strength of that attraction is holding the solid together. The strength of the attraction depends on distances between atoms, greater distance means lower attraction.

So, when an atom's temperature increases and its motion carries it to a point of lower attraction, it comes apart.

But yeah, its incorrect to say heat applies a force. Heat is a transfer of energy. I suppose you could say work (the other energy transfer) can be the result of a force, but as mentioned the force construct isn't necessary. That's because work can also be thought of as a change in kinetic energy.

 

[stefan r]

The units for energy and force are different
Energy: kg m²s^-2
Force: kg m s^-2

Energy is a measurement work done by a force over a distance.

 

[DrClaude]

what if we thinks of star's heat?? Is it not applying force on earth?

There is radiation pressure, but I wouldn't call that "heat applying a force".

 

[first martiAn]

But pressure exert force.

 

[jbriggs444]

But pressure exert force.

Radiation pressure from starlight is miniscule and does not directly correlate to the heat in the star. The point stands -- there is no underlying principle of physics which says that "heat applies force".

 

[russ_watters]

But pressure exert force.

Yes, but radiation pressure isn't heat!

 

[first martiAn]

A star is formed when a large amount of gas, mostly hydrogen, starts to collapse in on itself due to its gravitational attraction . As it contracts, the atoms of the gas collide with each other more and more frequently and at greater and greater speeds - the gas heats up.

 

[first martiAn]

So if gravity of molecules heat it up. Then why not heat can starts gravity to rise.

 

[jbriggs444]

So if gravity of molecules heat it up. Then why not heat can starts gravity to rise.

It seems that you are trying to reason that "if gravity can cause heat then heat must be able to cause gravity".

Counter-example:

If pulling the trigger on a gun causes a bullet to shoot out, does it follow that having a bullet shoot out will cause the shooter to pull the trigger again?

 

[ZapperZ]

A star is formed when a large amount of gas, mostly hydrogen, starts to collapse in on itself due to its gravitational attraction . As it contracts, the atoms of the gas collide with each other more and more frequently and at greater and greater speeds - the gas heats up.

The problem with your line of thought here is that you're trying to make "force" to be either as fundamental, or more fundamental, than energy. This is a path that will lead you to nowhere.

For example, I can have a value of energy, but I will have no force acting on it. An object in a constant potential energy is one such example. However, I cannot say this the other way around, i.e. I cannot say there is a force but there is no energy. Whenever there is a force acting, there MUST be a non-zero energy gradient.

Secondly, equating "pressure" with "force" is wrong. What is more "fundamental" here is the rate of change of momentum of each molecule of the gas. I can increase the temperature of the gas, but if there isn't any "container" for the molecule to bump into and exert a pressure, there will be no pressure and there is no force/area.

Finally, in classical and quantum mechanics, the Hamiltonian/Lagrangian formulation of the dynamics of a system contains no such thing as "force". There is only energy, momentum, position, etc.. but no force. If we were to teach this method to you from the very beginning instead of Newtonian mechanics, you will never know that there is such a thing as "force". It is not a necessary concept or quantity to describe our world.

Zz.

 

[Grinkle]

@first martiAn I think maybe you are looking for an effort / flow analogy to mechanical systems. Start here -

https://en.wikipedia.org/wiki/System_equivalence

If you don't yet have any calculus, it may be tough to get your head around.