Chapter 8: Angular Kinematics

Objectives:
  • Define:
    • Relative and absolute angular position
    • Angular displacement
    • Average angular velocity
    • Instantaneous angular velocity
    • Average angular acceleration
    • Instantaneous angular acceleration
  • Name units of measurement for above definitions
  • Explain the relationship between angular and linear motion
  • Define:
    • Tangential acceleration and explain its relationship to angular acceleration
    • Centripetal acceleration and explain its relationship to angular velocity and tangential velocity

 


Linear and Angular Quantities


Degrees and Radians
180 degrees = 3.14 radians
                           ANGULAR DISPLACEMENT
AVE ANGULAR VELOCITY = ---------------------------
                             CHANGE IN TIME
                            CHANGE OF ANGULAR VELOCITY
AVE ANGULAR ACCELERATION = ---------------------------
                                  CHANGE IN TIME


  • Slope of angular position versus time equals angular velocity
    Running Example -- Olympic Trials 5k Foot Strikes

  • Connection of Linear and Angular Velocity
  • V = ω * r
    Discuss how weight and length of golf clubs relates to the distance the club should hit.

  • Tangential Acceleration: The component of of linear acceleration tangent to the circular path of a point on a rotating object

    aT = α * r

  • Centripetal Acceleration: The linear acceleration directed toward the axis of rotation

    ar = ω 2 r


Hammer throw example