A) a negative charge is brought into an empty area: how much energy does that take? b) another negative charge is brought into the area: does this increase or decrease the energy of the system? c) a positive charge is brought into the area: does this increase or decrease the energy of the system?

The star betelgeuse is about 600 light-years away. if it explodes tonight, a. we'll know because debris from the explosion will rain down on us from space.b. we'll know it immediately because it will be brighter than the full moon in the sky.c. we won't know about it until 600 years from now.d. none of the above.