During heavy rain, a rectangular section of a mountainside measuring 2.7 km horizontally, 0.85 km up along the slope, and 2.5 m deep suddenly slips into a valley in a mud slide. Assume that the mud ends up uniformly distributed over a valley section measuring 0.40 km 0.40 km and that the mass of a cubic meter of mud is 1900 kg. What is the mass of the mud sitting above an area of 4.0 m2 in that section?