306 pre torque concepts

center of gravity (COG)

• imaginary point around which body’s weight is equally balanced in all directions

  • uniform = center

  • human = near sacrum

anthropometry

• the science that defines physical measures of a person’s size, form, and functional capacities

angular kinematics

• the kinematics of objects or systems underdoing angular motion

angular displacement

• change in angular position of a segment or any point on the rotating segment

relationship between angular motions of body and linear motion of a point on the segment`

• all points on body have same angular motion

• linear motion influenced by distance of the measured point from the axis of rotation (R)

tangent direction

• line that just touches the circular path of a point on rotating body

radial direction

• line connecting axis of rotation to a point on rotating body (radius)

relationship between linear distance and angular displacement

• linear distance (arc length) is proportional to radius and angular displacement

centripetal accel vs tangential accel

• centr - always when you spin

• tang - only when slowing or speeding

tangential accel

• points tangentially based on angular accel

centripetal accel

• always points towards axis and is how tangential velo changes direction