posted by Jonathon .
The density of air near the earth's surface is 1.29 kg?m^3. If a helium balloon with a mass of 1 kg floats in air without rising or falling,what is the minimum volume of helium in the balloon? (presume that the mass of the material making up the balloon is negligible). I am not looking for someone to give me the answer, just explain how to figure it out. like what formula to use?/? Thank you1!