1. The problem statement, all variables and given/known data A rectangular waterproof air mattress is 2.0m long, 0.50mwide and 0.08m thick. It has a mass of 2.0kg and is supporting an additional mass of m, while floating in the water, calculate the mass, m, assuming the density of water is 1000kg/m^3 and density of air is 1.29kg/m^3 2. Relevant equations B = weight of displaced fluid B= density of water x volume * g where B = mass of 2kg, unknown mass and mass of air 3. The attempt at a solution I solved it and i got 78.1kg. The answer is 79.9kg this is what i did: m1g + m2g + density(air) * V *g = density(water) * V * g solve for m2: m2 = density(water) * V - density(air) * V - m1 m2 = 1000(0.08) - 1.29(0.08) - 2 m2 = 78.1kg Can someone point out where i went wrong????