Question

Thermodynamics (Help)

Answer 1

I am not good at Thermodynamics, I hope it's a simple problem.

Answer 2

I'm a bit and somewhat confused with our lesson lately.
My Professor said that
Change in Phase = Thermal Energy
while
Change in Temperature = Heat Energy
Therefore
\[\Delta KE = Thermal Energy \]
while\[\Delta Temperature = Heat Energy\]
Then she said that
Thermal Energy is the Sum of \[\Delta KE + \Delta PE\]
and later on with the discussion
I tried to argue about why does Thermal Energy have to rely on the Principles of Work
and I was wondering why does PE have to be used in this process?

Any ideas or answer

Answer 3

I believe there is just some confusion about nomenclature here. First of all, thermal energy is measured by temperature, therefore an increase in temperature indicates an increase in thermal energy. However, an increase in thermal energy does not mean that the temperature changes. For example, when we boil water, we must first heat the water to 100C, then continue to add head (heat of fusion) while the temperature remains constant. This is why your teacher is making the distinction between "heat" and "thermal" energies.

By the same token as boiling water, we know that when water turns to stream, the velocity of the molecules increases. This is an increase in kinetic energy. The reason we monitor potential energy is because of the conservation of energy.

Let's look at the First Law, \[Q - W = \Delta U + \Delta KE + \Delta PE\]for a closed system. We can technically do work on a system by raising the entire system some height, thereby increasing the potential energy of the system.

You can also look here for another take on the subject: http://en.wikipedia.org/wiki/Thermal_energy#Distinction_of_thermal_energy_and_heat

Answer 4

I see. Thanks Bro.