A hydroelectric power station has a power output of 2.0 MW when water passes through its turbines at a rate of 1.4 ms. The water is supplied from a reservoir which is 750 m above the power station turbines, as shown in the diagram below. density of water 1000 kg m Calculate i. the mass of water passing through the turbines each second, ii. the loss of potential energy per second of the water flowing between the reservoir and the power station turbines, iii. the efficiency of the power station.