Because engine is capable of using the tires to produce a force equal to the maximum friction force, therefore the frictional produced by gravity can be ignored. Just consider the exhaust force, Fcosθ=μFsinθ, so the result is μ=1/tanθ. But that's not correct answer.
And the angle is measured...
Homework Statement
Top-fuel dragsters can accelerate from rest at a rate of about 5g. If this does not sound impressive, consider that for most automobiles the friction between the ground and the tires produces the acceleration. Since the coefficient of friction between regular treaded tires...