b
\({P_t}\, = \,\,{P_c}\,\left[ {1\,\, + \,\,\frac{{{m^2}}}{2}} \right]\,\, = \,\,9\,\left[ {1\,\, + \,\,\frac{{{{(0.4)}^2}}}{2}} \right]\,\, = \,\,9\left[ {1\,\, + \,\,\frac{{0.16}}{2}} \right]\,\)
\(\,(\because \,\,m\,\, = \,\,40\% \,\, = \,\,0.4)\) \( = \,\,9\,(1.08)\,\, = \,\,9.72\,\,kW\)