An aerodynamic 1000kg car takes about 270 newtons of force to maintain speed of 25m/s. Evaluate the work of the car.

In this question, my teacher answered 6750W since F times delta X, however, if I try to find the W through using the kinetic energy formula, which is 1/2mv^2, the answer will be 312500N. Why is this approach even wrong?

Didn't the kinetic energy formula find out the work done by objection in motion? I would like to know why F times Delta X (270N times 25m/s) only works in this question.