Question

What is the change in internal energy of a system that takes in 3.88 106 J of heat, and does 4.50 105 J of work while dissipating 7.92 106 J of heat

Answer 1

ΔU = -4.904 × 10^(5) J

Step-by-step explanation:

We are given;

Heat transfer into the system;Q1 = 3.88 × 10^(6) J

Heat transfer out of the system;Q2 = 7.92 × 10^(6) J

Work done; W = 4.5 × 10^(5) J

Now, the net heat transfer is the heat transfer into the system minus the heat transfer out of the system. Thus;. Q = Q1 - Q2

Q = (3.88 × 10^(6)) - (7.92 × 10^(6))

Q = -4.04 × 10^(6) J

The formula for change in internal energy is given by the first law of thermodynamics:

ΔU = Q - W

ΔU = (-4.04 × 10^(6)) - 4.5 × 10^(5)

ΔU = -4.904 × 10^(5) J

The negative sign means loss of internal energy