Trig question, I'm sure I'm being silly but help please....

[shott92]

so basically I have been trying to add into a car and circuit simulation wind speed and direction, now I was thinking that cos degrees would work fine, so "wind direction - driving direction = affective direction."
This works for head wind -1 and back wind 1 as well as side winds, 0 (no affect)
however I am really confused (I know that cos(45) is 0.707) but don't I want it to be 0.5?
I'm just thinking simply here that a 45 degree head wind will have a 50% impact on speed? yes? no?
please can someone tell me how I should be calculating the affective wind direction tanks
If I am being a complete twonk feel free to tell me.

 

[Nidum]

I'm just thinking simply here that a 45 degree head wind will have a 50% impact on speed? yes? no?

No to that .

A head wind will certainly tend to slow car down or require more engine power to maintain speed but there is no easy way to estimate the actual effect of a head wind using simple calculations .

Effective wind direction is not too difficult to work out though . Look up : Relative Velocity