In a heat engine, if 700 J of heat enters the system, and the piston does 400 J of work, what is the final internal (thermal) energy of the system if the initial energy is 1,200?
1,500
In the first law of thermodynamics, ΔE=Q−W , what does Q stand for?
q stands for heat
To find the final internal (thermal) energy of the system, you need to consider the conservation of energy. In this case, the change in internal energy (ΔU) is equal to the heat input (Q) minus the work done by the system (W).
ΔU = Q - W
Given that the heat input (Q) is 700 J and the work done (W) is 400 J, you can substitute these values into the equation:
ΔU = 700 J - 400 J
Subtracting these values, you get:
ΔU = 300 J
So, the change in internal energy of the system (ΔU) is 300 J.
To find the final internal energy, you need to add the change in internal energy (ΔU) to the initial internal energy (U_initial).
U_final = U_initial + ΔU
Given that the initial internal energy (U_initial) is 1,200 J and the change in internal energy (ΔU) is 300 J, you can substitute these values into the equation:
U_final = 1,200 J + 300 J
Adding these values, you get:
U_final = 1,500 J
Therefore, the final internal (thermal) energy of the system is 1,500 J.