Two long barges are moving in the same direction in still water, one with v1 = 10km/h and the other with v2 = 20 km/h. While they are passing each other, coal is shoveled from the slower to the faster one at a rate of 1000 kg/minute. How much additional force must be provided by the driving engines of the faster barge if it is to maintain a constant forward speed? Assume that the shoveling is always perfectly sideways, and that the frictional forces between the barges and the water do not depend on the mass of the barges.
The boats are same lengths widths etc. Their dimensions are same.