How do tornadoes form from thunderstorms when .

a. rising unstable air forms rotating winds b. rising stable air form cumulus clouds. c. falling unstable air forms a cold air mass. d. falling stable air forms pressure changes.

"an open tank has the shape of a right circular cone. the tank is 6 feet across the top and 5 feet high. how much work is done in emptying the tank by pumping the water over the top edge? note: the density of water is 62.4 lbs per cubic foot."