Non-conservative forces, like friction or air resistance, really change how we think about mechanical energy. Let’s break it down:

• Energy Loss: These forces take mechanical energy and change it into other types, like heat. For example, when a skateboard rolls and starts to slow down, the energy isn’t just 'lost'—it’s changing into heat because of friction.

• Math Perspective: The way we look at mechanical energy changes a bit. Instead of just thinking about energy being saved, we have to include the work done by these non-conservative forces. It looks like this: $E_{\text{initial}} + W_{\text{nc}} = E_{\text{final}}$

• Real-Life Example: Picture yourself sliding down a slide. You speed up, but friction between you and the slide takes away some of that energy!

In summary, non-conservative forces take away energy and show us that energy can change into different forms in the real world!