A barge floating in fresh water ( = 1000 kg/m³) is shaped like a hollow rectangular prism with base area A = 550 m² and height H = 2.0 m. When empty the bottom of the barge is located H₀ = 0.45 m below the surface of the water. When fully loaded with coal the bottom of the barge is located H₁ = 1.3 m below the surface.

a. Find the mass of the coal in terms of the given data.

b. Find the mass of the coal in kilograms.