Suppose there is a wind with velocity $v \ll c$, which is blowing on a person who is moving at velocity $u \ll c$ (both in the $x$-direction). In the rest frame of the person, the wind exerts a force $F$ on the person, where $F$ is proportional to $(v-u)^2$.
Now, say there is an observer moving in the $x$-direction at velocity $w$, which is close to the speed of light. Is there a difference in the force that the observer sees, or is it the same as in the rest frame of the person?