4.1 Water from a well is used to irrigate (center pivot irrigation system) an organic vegetable field. The field is 75 Ha in size and water must be supplied at the rate of 3.9 mm per day to account for evapotranspiration. How many cubic meters of water must be pumped per day to meet the needs of the growing crop? 

4.2 The well that supplies water to the irrigation system is 1,900 feet deep (depth from soil surface to water level in well). Assume the pump is to run no more than 8.0 hour per day to pump enough water to meet the needs of the growing crop in problem 4.1 above. What pumping capacity is needed to meet this requirement (liters/minute)? 

4.3 Estimate the power requirement (kW) to drive the pump in problem 4.2 above. 

4.4 An electric motor is used to drive the well pump. When operating at 480 Volts AC, the motor draws a current of 805 A. What the overall efficiency (expressed as %) of the pump and motor combination? 

4.5 If electricity costs $0.127 per kWh, what is the daily cost of irrigating the 75 ha field?