6 ms·
How are heat and entropy different?
by ainoobler 2y ago
How are heat and entropy different?
- tsimionescu 2y agoHeat is energy that causes something to raise in temperature, and is measured in Joules. Entropy is a harder to pin down concept, related to the internal state of a system, and is measured in Joules/kelvin. In certain processes, the change in entropy is equal to the change in heat divided by the temperature of the system.
- ainoobler 2y agoSounds like it's the same thing.
- tsimionescu 2y agoIt is not. Two bodies can have different entropy even if they are emitting the same amount of heat.
- ainoobler 2y agoWhere are the calculations?
- tsimionescu 2y agodS = dQ / T
- ainoobler 2y agoSo T = dQ/dS. Seems like the same thing.
- tsimionescu 2y agoIf they were the same thing, then T=1. Since there are many many bodies with T != 1, it follows that dQ is rarely equal to dS.
- HPsquared 2y agoThey are closely related but not the same. DeltaS = DeltaQ /T A lot of it comes down to whether a process is reversible or not. I've taken multiple courses on thermodynamics and still only understand it a little.