The free-body force diagram below represents two forces, F1 and F2, acting on a hot air balloon as it rises through the air. If the net force acting
on the balloon is 120 N upward, what is the magnitude of F2?"
P, - 1100N

Heat can be transferred thru multiple ways. since the foil is shiny, and reflective, if one puts it over the windows of the house, for example, the heat that would go through the windows, which aren't very good insulators, causing the heat to be reflected back into the house.