I get when atoms split the basic paticals are still there. So no matter is destryed. But the energy released does last so briefly (ie an explosion). I remember burning peanuts in school and weighing them before and after. The weight difference showed that matter had become energy. Of course we couldn't weigh the lost steam vapor, or any ash lost to the burning that wafted off to the air.
I get potential verses kinetic energy but once the ball drops that energy is gone.
Are we not creating energy (potential) when we lift that ball again? Energy taken from the muscle movement to lift it. Then that energy is gone when the ball drops.
That energy came from the muscle that came from the o2 and food we ate and drank, that came from the meat that came from the gras that came from the sun.
BUT when the ball drops, the piston fires, where does that energy go? Is it not lost? Destryed?