Question

Why is energy released when binding energy increases?

Answer 1

Let's draw an analogy: suppose we do not talk about nucleons (and nuclear forces) but about a weight that can fall to the earth (gravitational forces). If we start at 10 m height but let the weight drop (through a cable on a pully), would you agree that if we let it drop further (more bound to earth) we could get out more energy for doing work (raising another weight for instance). I hope this simple analogy makes it clear that binding energy is the depth of a potential energy well. You would need to put in more energy to get a bucket up from deeper inside a water well, wouldn't you agree? Energy conservation then let's you conclude that more energy is released when you drop the bucket deeper. Again, the same principle at work here.