• Examine how to describe a body's position
• Define how to determine the number of independent quantities (called degrees of freedom) necessary to describe a point or a body in space
• Define how to measure and calculate changes in linear position (displacement) and the time derivatives velocity and acceleration.
• Define how to measure and calculate changes in angular position (angular displacement) and the time derivatives angular velocity and angular acceleration
• Describe how to present the results of a kinematic analysis
• Explain how to directly measure position, velocity, and acceleration by using motion capture systems or transducers

Description of Position

Is a runner 60 m from the start or 40 m from the finish?

Line up on the 20 yd line.

What is the position of my knee?

x, y, z, θx, θy, and θz

• How many camera views are needed to obtain x, y data?
• How many camera views are needed to obtain x, y, z data?
• How many points are needed to obtain θx, θy, and θz?

Calibration

Two-Dimensional

• Scaling Rod
  • s = actual length (m) / digitized length (pixels)
  • x = su
  • y = sv

Distance:The length of a curve or line

Displacement: Change of position (Straight-line distance from start to finish)

Time Derivatives

• Speed: Distance / Time
• Velocity: Displacement / Time
• Acceleration: Velocity / Time

Mini-Project #1