Solve the Problem $\mathrm { P } \left( \right.$ In $\mathrm { W }$

Solve the problem.
-The power $\mathrm { P } \left( \right.$ in $\mathrm { W }$ ) generated by a particular windmill is given by $\mathrm { P } = 0.015 \mathrm {~V} ^ { 3 }$ where $\mathrm { V }$ is the velocity of the wind (in mph) . Find the instantaneous rate of change of power with respect to velocity when the velocity is $10.3 \mathrm { mph }$ .

A) 10.6 W/mph
B) 4.8 W/mph
C) 32.8 W/mph
D) 0.5 W/mph