You are driving north through an intersection in a 55 $mi/hr$ speed zone, when the local chief of police, who is driving his new cadillac and approaching the intersection from the west, hits you broadside. the two cars stick together and skid a distance 26.8 $m$ with locked wheels at an angle of 66.7° to the east of north. the mass of your car is 1474.0 $kg$ while the cadillac has a mass 1973.0 $kg$. the coefficent of sliding friction is 0.90. the chief of police is angry that you have damaged his new cadillac and gives you a ticket for speeding. the local judge is going to believe his chief of police rather than some out-of-town student. you realize that the knowledge you learned in your physics course is your only hope for acquittal. compute the speed of the chief of police immediately prior to the collision.

The inside surface of a cylindrical-shaped cave of inner diameter 1.0 m is continuously covered with a very thin layer of water. the cave is very long and it is open on both ends. the water on the cave surface is at a constant temperature of 15.5 °c. the cave is constantly exposed to wind such that 15.5 °c air flows through the cave at 4.5 m/s. the kinematic viscosity of the air is 14.66 x 10-6 m2/s and the molecular diffusion coefficient of water vapor in the air is 0.239 x 10-4 m2/s. because the cave diameter is so large, the flow of wind down the length of the cave, in the x direction, can be treated like it is external flow and the cave surface can be approximated as flat where appropriate. calculate the x value, in a) the transition to turbulent flow occurs at rex meters, where the air flow transitions from laminar to turbulent along the inside surface of the cave b) calculate the x value, in meters, where the bulk steady state concentration of water vapor in the air flowing in the cave is 10% of the saturation concentration. assume the air at the surface of the water layer is 100% saturated with water vapor. assume the wind entering the cave contained no moisture before it entered the cave. take into account the transition from laminar to turbulent flow when solving part b