Answer:
<em>-2 units of charge</em>
Explanation:
charge on A = Qa = -6 units
charge on B = Qb = 2 units
if the spheres are brought in contact with each other, the resultant charge will be evenly distributed on the spheres when they are finally separated.
charge on each sphere will be = 
charge on each sphere =
=
= <em>-2 units of charge</em>
The transfer of heat from the Sun is in the form of thermal radiation (also called infrared radiation)
The transfer of heat at the person’s feet is by thermal conduction. During the day the sand will be hot so if you step on it with bare feet there will be conduction of heat to the feet.