assuming 70kg per man 2 - Estimate: How much coal did each miner have to remove from the mine each day to ensure that a cage full of men could leave the mine at the end of a shift? How does this compare with his own weight? (I wonder if this is where the expression "pulling his weight" comes from?). Strategy: a) Visualize the system. There are many processes to this operation. Draw a schematic, showing each separate process unit, how they are all connected, and what the inputs and outputs are in terms of mass, energy, and work (please no numbers here yet!). Label all process units and define all variables, with units