(a) what are the three ultimate sources of energy on earth? 12] (b) wind energy is the most important renewable energy source that is used to generate electricity in ireland in 2015 accounting for 22.8% of electricity consumption. if the wind flows through a horizontal axis wind turbine (swept area of the turbine a) at a speed of v, as schematically shown in figure q3(b), write an equation for the power of the wind p (i. e. kinetic energy of the wind per unit time) that flows through the wind turbine. the density of air is p wind speed v swept area of wind turbine a figure q3(b) schematic diagram of wind flowing through a wind turbine (c) according to the power of wind that you formulated using your answer to (b), specify the most 14] important factor that affects the power of wind that blows the wind turbine. (d) practically, when the wind speed is relatively high (e. g. higher than 20 m/s up to 25 m/s as shown in figure q3(d) on the next page), the wind turbine can only convert a very small part of the overall wind power (kinetic power in figure q3( to generate electricity (output in figure q3( explain the reason for the large gap between the wind power and the electrical 14] output power (e) in the history of the development of wind turbine, wind turbines have been becoming bigger and bigger. explain the benefit that we can get by building large wind turbines compared with small ones. also explain the potential challenges when wind turbines become very large.