Moving fan has rotational kinetic energy
Non moving fan has no energy since it is in rest
The coolant gas in a fridge takes heat from the fridge and "pumps" or "dumps" it in the outside. The back of a working fridge is usually quite warm, and one source of that heat is the contents of the fridge.
Electrical energy is used to pump the coolant round the various components of the fridge's cooling system. It also possibly powers any lights in the fridge. That funny whirring sound may well be a motor, and motors are driven by electrical energy. If your power goes off, then your fridge stops fridging. all the stuff in the fridge warms up to room temp slowly, and you may end up with some "too warm" grub.
I believe its "Neutrons" because it is said to be neutral and it's a subatomic particle which is present in the nucleus of an atom.
D
The comet has no net force acting on it, which results in constant velocity. Near our solar system, the influence of the gravitational forces due to the sun and the planets will increase as we know that gravitational force is:
F = GMm/r²
The net force will produce an acceleration on the comet, which will cause its velocity to change.