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.

Part (a)  Using the information provided above, determine the simplest expression that George can use to determine the force of air resistance, F, on his car that is dimensionally correct. 

F =