Physical changes: melting, evaporating, and condensation. This is a physical change.
It could result in it not being good for your joints, as well as in the long run but shouldn't cause problems when your a child. I hope this helps your question!
Answer:
A stone on the ground does not have zero energy…there is an internal potential in every object. Aldo is not in action or in any mechanical motion it is being acted upon by gravity and also molecular forces and energy.
<em>Hope</em><em> </em><em>this</em><em> helps</em><em> </em><em>!</em>
The conservation of energy always holds true even when not clearly observable in machines that are less than 100% efficient. More often than not a machine will suffer energy losses (e.g. consider for a cooling fan: friction between the rotating blades, drag resistance in the air the fan is pushing around, resistance in the wire, and heat radiating/conducting away from the circuitry).
