George is trying to determine the effect of air resistance on his automobile. he finds that force (f) in newtons (a newton being kg⋅m/s2), depends on the speed at which his car travels (v), in m/s, the air surface area (a) of his car's front, in m2, the density of the air around his car (d), in kg/m3 and a unitless friction coefficient (χ). the friction coefficient is similar to that used in determining the force due to kinetic friction.