1. The Ladybugs are undergoing translational motion The disc is experiencing rotational motion. What’s the difference?

2. Translational Motion movement of the centre of mass Rotational Motion movement around the centre of mass; centre of mass remains stationary

3. Translational Motion movement of the centre of mass linear and circular motion Rotational Motion Movement around the centre of mass; centre of mass remains stationary

4. Translational Motion movement of the centre of mass linear and circular motion Rotational Motion Movement around the centre of mass; centre of mass remains stationary Spinning motion

5. Translational Motion movement of the centre of mass Includes linear and orbital/circular motion In orbital motion the CofM of object moves around the centre of rotation at a set radius and a corresponding velocity Rotational Motion Movement around the centre of mass; centre of mass remains stationary Spinning motion

6. Translational Motion movement of the centre of mass Includes linear and orbital/circular motion In orbital motion the CofM of object moves around the centre of rotation at a set radius and a corresponding velocity Rotational Motion Movement around the centre of mass; centre of mass remains stationary Spinning motion In rotational motion the CofM is at the centre of rotation.

7. Translational Motion movement of the centre of mass Includes linear and orbital/circular motion In orbital motion the CofM of object moves around the centre of rotation at a set radius and a corresponding velocity Rotational Motion Movement around the centre of mass; centre of mass remains stationary Spinning motion In rotational motion the CofM is at the centre of rotation. Radius and velocity aren’t useful anymore because they are different for each point on the object!

8. Translational Motion In orbital motion the CofM of object moves around the centre of rotation at a set radius and a corresponding velocity Pure Translational motion occurs when forces act thru the centre of mass Rotational Motion In rotational motion the CofM is at the centre of rotation. Radius and velocity aren’t useful

9. Translational Motion In orbital motion the CofM of object moves around the centre of rotation at a set radius and a corresponding velocity Pure Translational motion occurs when forces act thru the centre of mass Rotational Motion In rotational motion the CofM is at the centre of rotation. Radius and velocity aren’t useful Pure Rotational Motion occurs when forces act in equal and opposite “force couples” that act a distance apart

10. Translational Motion Pure Translational motion occurs when forces act thru the centre of mass Try it: Rotational Motion Pure Rotational Motion occurs when forces act in equal and opposite “force couples” that act a distance apart Ruler push

11. Translational Motion Pure Translational motion occurs when forces act thru the centre of mass Try it: Rotational Motion Pure Rotational Motion occurs when forces act in equal and opposite “force couples” that act a distance apart Ruler push Ruler push

12. Translational Motion Pure Translational motion occurs when forces act thru the centre of mass What happens if? Rotational Motion Pure Rotational Motion occurs when forces act in equal and opposite “force couples” that act a distance apart Ruler push Motions are often both translational and rotational at the same time