Answer:
581 kJ, work was done by the system
Explanation:
According to the first law of thermodynamics:

where
is the change in internal energy of the system
Q is the heat absorbed by the system (positive if absorbed, negative if released)
W is the work done by the system (positive if done by the system, negative if done by the surrounding)
In this problem,


Therefore the work done by the system is

And the positive sign means the work is done BY the system.
This interaction is known as <em>constructive interference</em>. It's a result of linear superposition.
Answer:
In the air
Explanation:
There are three states of matter:
- Solids: in solids, the particles are tightly bond together by strong intermolecular forces, so they cannot move freely - they can only vibrate around their fixed position
- Liquids: in liquids, particles are more free to move, however there are still some intermolecular forces keeping them close to each other
- Gases: in gases, particles are completely free to move, as the intermolecular forces between them are negligible
For this reason, it is generally easier to compress/expand the volume of a gas with respect to the volume of a liquid.
In this problem, we are comparing water (which is a liquid) with air (which is a gas). From what we said above, this means that the change in volume is larger in the air rather than in the water.