A system initially has an internal energy U of 493 J. It undergoes a process during which it releases 107 J of heat energy to the surroundings, and does work of 225 J. What is the final energy of the system, in J?
what is 493-107-225?
To determine the final energy of the system, we need to consider the energy balance equation which states that the change in internal energy (ΔU) of a system is equal to the heat energy (Q) added or removed from the system, plus the work (W) done by or on the system:
ΔU = Q + W
In this case, we are given that the system releases 107 J of heat energy (Q = -107 J) to the surroundings, and does work of 225 J (W = 225 J).
Substituting these values into the energy balance equation, we can calculate the change in internal energy (ΔU):
ΔU = Q + W
ΔU = -107 J + 225 J
ΔU = 118 J
The change in internal energy (ΔU) represents the difference between the final energy (Uf) and the initial energy (Ui) of the system:
ΔU = Uf - Ui
Rearranging the equation, we can find the final energy (Uf):
Uf = Ui + ΔU
Uf = 493 J + 118 J
Uf = 611 J
Therefore, the final energy of the system is 611 J.