Material use in wind turbine manufacturing. Approximately 65 gigawatts of electrical power are consumed during periods of peak demand in texas. If the entire demand were to be met by wind power and the wind turbines require 25 kg of dysporsium per megawatt of power generated, calculate the total amount of Dy required to manufacture these turbines, and compare this quantity to the total worldwide production of Dy (see U. S. DOE, 2010).

What precautions should you take to prevent injuries when dealing with heavy loads?

An electrical motor raises a 50kg load at a construct velencity .calculate the power of the motor, if it takes 40sec to raise the load through a height of 24m(take g =9.8n/g)

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?