posted by Hannah .
A balloon weighing 80 kg has a capacity of 1200 m3. If it is filled with helium, how great a payload can it support? The density of helium is 0.18 kg/m3 and the density of air is 1.30 kg/m3. Express your answer in Newtons.
I know the answer is 12, 400 Newtons I just don't know how to get that answer. I also have a quiz over this on Tuesday so hopefully someone can help... fast! Thanks<3