Using the AASHTO procedure, determine the thickness required for a base and a surface layer over existing subgrade. The structural number required for this pavement is 4.5. The available materials are a crushed stone base course with a material layer coefficient of 0.13 and an HMA surface with a material layer coefficient of 0.40. The drainage coefficient of the based course can be considered as 0.90.

Asimple speed reducer is composed of 2 spur gears. the pinion gear has a pitch diameter of 0.75" and 36 teeth while the driven gear has a pitch diameter of 4.0" and 192 teeth. a)-what is the diametral pitch of each gear? b)-if an electric motor rotating ccw at 3000 rpm is coupled to the pinion, what is the rotational speed of the driven gear? c)-if the torque delivered to the pinion is 1 n-m, what is the torque on the driven gear? d)-what is the power transmitted by the gear train?