READING QUIZ angular acceleration. angular velocity. angular mass. Torque primarily depends on: angular acceleration. angular velocity. angular mass.

Rotational Inertia The resistance to change in rotational motion. Torque = Moment of inertia x angular acceleration Moment of Inertia = Mass x distance from axis squared

Figure 8.15 Expressions for the rotational inertia of several objects, each with a uniform distribution of mass over its volume. The letter m is used to represent the total mass of the object.

Physics of Angular Motion If the total torque on an object is zero, then it does not rotate, or it rotates at a constant angular velocity. Physics of Linear Motion If the total force on an object is zero, then it does not move, or it is in linear motion with constant velocity

CONCEPT Rotational Inertia m I Second Law F=ma  Momentum P=mv L=I Linear Motion Rotational Inertia m I Second Law F=ma  Momentum P=mv L=I conservation P=constant, if F=0. L=constant, if  Kinetic energy KE=1/2mv2 KE=1/2I2

Fig. 8.16 Fig. 8.16

Physics of Angular Motion If the net torque on a system is zero, the total angular momentum of the system is conserved. L=I L = vector I = Tensor w = vector

Fig. 8.17 Fig. 8.17

Fig. 8.18 Fig. 8.18

Fig. 8.20 Fig. 8.20 Rotational velocity is a vector. Use the right hand rule to find the direction…..

Fig. 8.23

Fig. 8.24 Fig. 8.24