Question

A real spring does not oscillate forever. Instead, it eventually comes to a stop. Does this violate the Law of Conservation of Energy? Explain why or why not.

Answer 1

clearly not.

"Missing" energy almost always winds up as heat.

Answer 2

the energy "lost" is converted to heat energy. If you did this in a perfectly insulated box, you would see the temperature rise as the spring slowed down.

Answer 3

By the way I gave you a simple answer because you asked the simple question.
However if you sense that something was lost as the spring wound down, even if not the total energy, you would be right. This is related to the physics or physical chemistry course you take next year, the concept of "entropy" and the reason perpetual motion does not happen. During the slowing of the spring, the capability to do useful work with the energy decreased.

Answer 4

The usual example is that if you have a cup of water at 100 degrees and another at zero degrees, you can run a machine with the energy available between them. However if you mix them and have two cups at 50 degrees, the total energy is the same, but the ability to run your engine is gone.