Aspecimen of dry sand was subjected to a direct shear test. a normal stress of 120.0 kn> m2 was imposed on the specimen. the test was carried out until the specimen sheared, with a shear stress at failure of 75.0 kn> m2. determine the sand’s angle of internal friction.

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?