A wind tunnel can be used to model the effect wind has on an airplane. what is one limitation of this model? A. Pieces of planes, such as wings, can be tested.
B. Highly skilled workers are necessary to run the wind tunnel.
C. The airflow in the tunnel can be varied to mimic atmospheric conditions
D. A wind tunnel provides valuable information about how planes fly

A75-hp (shaft output) motor that has an efficiency of 91.0 percent is worn out and is to be replaced by a high-efficiency motor that has an efficiency of 95.4 percent. the motor operates 4368 hours a year at a load factor of 0.75. taking the cost of electricity to be $0.12/kwh, determine the amount of energy and money saved as a result of installing the high-efficiency motor instead of the standard motor. also, determine the simple payback period if the pu