A $1000\ \text{kg}$ car climbs a slope that rises $1\ \text{m}$ for every $20\ \text{m}$ along the road, at a steady $15\ \text{m/s}$, against $400\ \text{N}$ of drag and friction. Taking $g = 9.8\ \text{m/s}^2$, what power must the engine deliver?