We call the first law of thermodynamics the principle of energy conservation applied to thermodynamics, which makes it possible to predict the behavior of a gas system when undergoing a thermodynamic transformation.
Analyzing the principle of energy conservation in the context of thermodynamics:
A system cannot create or consume energy, but only store it or transfer it to its environment, as work, or both at the same time, so when it receives a quantity Q of heat, it may do some work and increase the internal energy of the system ΔU, that is, expressing mathematically:
Being all units measured in Joule (J).
Knowing this law, we can observe its behavior for each of the presented quantities:
|Heat||Job||Internal Energy||Q //ΔU|
|don't trade||does not perform or receive||doesn't vary||=0|
(1) When receiving a quantity of heat Q = 50J, a gas performs a work equal to 12J, knowing that the internal energy of the system before receiving heat was U = 100J, what will this energy be upon receipt?