10.5.Set Up:Let counterclockwise torques be positive. Solve:counterclockwise.Reflect:It is important to take into account the direction of each torque when computing the net torque.10.6.Set Up:Let the direction the wheel rotates be positive.Solve:10.7.Set Up:The applied force has moment arm Solve:gives10.8.Set Up:Assume the wheel is initiallyturning clockwise and take this to be the positive sense of rotation.Solve:Use the information about the motion to find givesFriction exerts a torque of in the direction opposite to the motion.10.9.Set Up:Let the direction the grindstone is rotating be positive. From Table 9.2,Use theinformation about the motion to calculate In must be in Solve:givesThe net torque is due to the kinetic friction force between the ax and the grindstone. givesandso Reflect:relates the forces on the rotating object to the motion of the object.10.10.Set Up:Apply to the bucket, with downward. Apply to the cylinder, with thedirection the cylinder rotates positive.
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