A balloon of air deflated and does 300kj of work to the surrounding. While deflating the air inside the balloon transfers 60kj of energy to the outside of the balloon. What is the total change of the air inside the balloon when it deflates?

1 answer

To analyze the deflation of the balloon, we need to consider the changes in the internal energy, work, and heat transfer of the air inside.

The total change in the internal energy of the air inside the balloon can be calculated using the First Law of Thermodynamics:

ΔU = Q - W

where ΔU is the change in internal energy, Q is the heat transfer, and W is the work done by the system.

Given that the air inside the balloon does 300 kJ of work on the surroundings, the work done by the air inside the balloon is negative:

W = -300 kJ

During the deflation, the air inside the balloon transfers 60 kJ of energy to the outside, which means there is heat transfer from the air inside to the surroundings:

Q = -60 kJ

Plugging these values into the First Law of Thermodynamics equation, we find:

ΔU = -60 kJ - (-300 kJ)
ΔU = -60 kJ + 300 kJ
ΔU = 240 kJ

Therefore, the total change in the internal energy of the air inside the balloon when it deflates is 240 kJ.