No, it doesn't. The grounding wire is an equipment ground. It connects to metal cases and other points inside the device that require an earth ground, and not all devices actually require an earth ground. Electrically, though, it does nothing for the cord itself or the outlet.
The sparks are caused by the physical design of the plug and outlet, specifically that US outlets are designed in such a way that you can actually see them. Any mechanical connection between two conductors (outlets, switches, etc.) has the potential to spark if the voltage between them is high enough. Other conductors have nothing to do with this potential.
The sparks are caused by the physical design of the plug and outlet, specifically that US outlets are designed in such a way that you can actually see them. Any mechanical connection between two conductors (outlets, switches, etc.) has the potential to spark if the voltage between them is high enough. Other conductors have nothing to do with this potential.