The balloon of air inflated which does 475kj of work to the air in the balloon. the balloon then received 35kj of energy from the surrounding air. How much internal energy did the gas inside the balloon gain or lose?

1 answer

To determine the change in internal energy of the gas inside the balloon, we need to consider the work done on the gas and the energy transferred to it.

Given:
Work done on the gas = 475 kJ
Energy transferred to the gas = 35 kJ

The change in internal energy (ΔU) can be calculated using the first law of thermodynamics, which states that the change in internal energy of a system is equal to the sum of the heat added to the system and the work done on the system:

ΔU = Q + W

Where:
ΔU = change in internal energy
Q = heat added to the system
W = work done on the system

In this case, the work is done on the gas, so W is positive (+475 kJ). The energy transferred to the gas from the surrounding air is heat, so Q is positive (+35 kJ).

Substituting the given values into the equation:

ΔU = 35 kJ + 475 kJ
ΔU = 510 kJ

Therefore, the gas inside the balloon gained 510 kJ of internal energy.