A large rock became visible to a driver at a distance of 175 ft. Assuming a perception-reaction time of 0.8 s, an initial speed of 42 mi/h, a coefficient of friction of 0.5, and a level roadway, calculate the speed at impact.

Derive the correction factor formula for conical nozzle i=-(1+ cosa) and calculate the nozzle angle correction factor for a nozzle whose divergence hal-fangle is 13 (hint: assume that all the mass flow originates at the apex of the cone.