A car moving along a horizontal road has a maximum useful output power of $P$. The overall resistive force on the car is $kv^2$, where $v$ is the car’s speed and $k$ is a constant. Which equation is correct when the car is moving at maximum speed?
- A$v^3 = \frac{P}{k}$
- B$v^2 = \frac{P}{k}$
- C$v = \left(\frac{P}{k}\right)^2$
- D$v = \left(\frac{P}{k}\right)^3$