Angular Kinematics Flashcards
Define Angular kinematics
Description of the circular motion or rotation of a body
- Define Motion (described in terms of variables)
Angular position and displacement
Angular velocity Angular acceleration Angular acceleration
Define Rotation of body segments
e.g. flexion of forearm about transverse axis through elbow joint centre
Define Rotation of whole body
e.g. rotation of body around centre of mass (CM) during somersaulting.
Define Rotation about a fixed point
e.g. the floor, high bar.
What is the Revolutions unit used for.
(Rev) normally used to quantify body rotations in diving, gymnastic etc.
What is the Degrees unit used for.
Normally used to quantify angular position, distance and displacement.
Convert Degrees to Radians both ways.
Convert degrees to Radians by dividing by 57.3 approximately.
Convert Degrees to Radians to Revolutions.
360 degrees= 1 Rev= 2 pie rads.
180 degrees= 1/2 Rev= pie rads.
90 degrees= 1/4 Rev= pie/2 rads.
Explain the rule that describes the angular motion and vector relationship.
The right-hand thumb rule.
- Fingers of the right hand curled in direction of rotation.
- Direction of extended thumb coincides with the direction of the angular motion vector.
- Counter clockwise rotations are positive.
- Clockwise rotations are negative.
Name and define the two types of angles.
-
Absolute angles
Angle of a single body segment, relative to (normally) a right horizontal line (e.g. trunk, head, thigh). -
Relative angles.
Angle of one segment relative to another (e.g. knee, elbow, ankle).
Define Angular distance.
The sum of all the angular changes of a rotating body between it’s initial and final positions.
Denoted by triangle, feta.
Define Angular displacement.
Calculated by feta 2- feta 1. (Just angle 2 - angle 1).
Define Angular velocity.
The w sign.
Angular velocity= angular displacement/change in time. Units degrees/per/sec.
Define Angular acceleration.
a - alpha sign.
Angular acceleration= change in angular velocity/change in time.
