At a certain location, wind is blowing steadily at 18 m/s. Determine the mechanical energy of air per unit mass and the power generation potential of a wind turbine with 80-m-diameter blades at that location. Also, determine the actual electric power generation, assuming an overall efficiency of 30 percent. Take the air density to be 1.25 kg/m3.

Explanation:

Given data

Diameter d=80m

Speed v=18 m/s

Efficiency n=30%

Air density p=1.25 kg/m³

For Mechanical energy of air per unit mass

The power potential of wind per unit mass could be defined as follow:

For  Power generation potential

The generation potential of turbine will determined from the available kinetic energy of air:

For Actual power

The actual power generation could be defined as follow as:

i am pretty sure it is c because when people are closer together, they cannot move as freely. picture being in a mostly full elevator, for instance. the people are right next to you, and you can barely move.