1. Rotational Energy Kinetic Energy ( E k ) - The ability to produce change due to an object’s motion. Linear Kinetic EnergyRotational Kinetic Energy

2. Rotational Energy Example 2.A rigid body is made of three identical thin rods, each with length l, fastened together in the form of a letter H. The body is allowed to fall from rest from a position in which the plane of the H is horizontal. a.What is the rotational inertia of the H? Since rod 1 has no radius Since rod 2 is a thin rod rotated about one end Since rod 3 acts like a hoop with all mass a distance l away from the axis of rotation

3. Rotational Energy Example 2.A rigid body is made of three identical thin rods, each with length l, fastened together in the form of a letter H. The body is allowed to fall from rest from a position in which the plane of the H is horizontal. b.What is the angular speed of the body when the plane of the H is vertical?? Use the Law of Conservation of Energy Must use the center of mass to determine y i

4. Rotational Energy Example 2.A rigid body is made of three identical thin rods, each with length l, fastened together in the form of a letter H. The body is allowed to fall from rest from a position in which the plane of the H is horizontal. b.What is the angular speed of the body when the plane of the H is vertical?? Must use the center of mass to determine y i