The costs of mining and transporting coal are roughly independent of the heating value of the coal. Consider:
(1) that the coal in the ground is valued at 50 cents/(million kJ),
(2) that mining costs are 8 dollars/tonne, and
(3) that transportation costs are 8 cents/(tonne/km). If the price of other delivered coals is 160 cents/(million kJ)
(Find the radius from the mine, in kilometers, that a coal of 32,560 kJ/kg can be delivered and sold for zero profit or loss
