Answer:
I believe that the answer is D. There are drilling platforms all along the coast that are used to drill for natural gas that can be used to generate electricity.
Explanation:
Solar panels use the sun, and that is renewable.
The power plant uses tides and waves, they are renewable.
Windmills use wind, that is renewable.
So, the answer is D.
Explanation:
It is given that,
Length of the helicopter, l = 3.1 m
The helicopter rotates, the length of helicopter will become the radius of circular path, r = 3.1 m
Angular speed of the helicopter, 
(a) The centripetal acceleration in terms of angular velocity is given by :



(b) Let v is the linear speed of the tip. The relation between the linear and angular speed is given by :


v = 90.89 m/s

Hence, this is the required solution.