Question

Example 10.8 Rotating Rod A uniform rod of length L 1.6 m and mass 2.8 k is attached at one end to a frictionless pivot and is free to rotate about the pivot in the vertical plane as in the figure. The rod is released from rest in the horizontal position. What are the initial angular acceleration of the rod and the initial translational acceleration of its right end Pivot SOLVE IT Mg A rod is free to rotate around a pivot at the left end. The gravi onal force on the rod acts at Conceptualize Imagine what happens to the rod in the its center of mass. figure when it is released. It rotates clockwise around the pivot at the left end. Categorize The rod is categorized as a rigid object under a net torque. The torque is due only to the gravitational force on the rod if the rotation axis is chosen to pass through the pivot in the figure. We cannot categorize the rod as a rigid object under constant angular acceleration because the torque exerted on the rod and therefore the angular acceleration of the rod vary with its angular position. Analyze The only force contributing to the torque about an axis through the pivot is the gravitational force Mg exerted on the rod. (The force exerted by the pivot on the rod has zero torque about the pivot because its moment arm is zero To compute the torque on the rod e assume the gravitational force acts at the center of mass of the rod as shown in the figure Write an expression for the magnitude of Mg the torque due to the gravitational force about an is through the pivot:

Answer 1

soluion about 12 , เช่า 2. Plro 3 8 1.6 m rata m Phank yoy