KINE 3050 Angular Kinematics Interactive Notes

What describes angular motion the most accurately

All parts of the object do not move the same distance

What exhibits angular motion around our joints?

body limbs

Angles are measures of

the orientation of 2 lines or planes that intersect

• measured by the symbol θ

What is a relative angle?

angles between 2 body segments regardless of their body positions 

Absolute angles

is always described in reference to a constant line such as the ground or a position that is perpendicular to the surface

What kind of angle is a bicep curl 

relative 

What is the SI unit for angular displacement?

radian

What is the size of the angle that is equal in length to the radius of the circle?

Radian

• there are 2 radians in a circle

How many degrees are in 1 radian?

57.3 degrees

Center of rotation is the

point around which it rotates

Levers: COR = fulcrum

center of rotation moves during the movement

What are the angular kinematic variables ?

Angular displacement is a

vector

• the change in absolute angular position

• expressed in degrees and radians (rad)

Angular displacement has a

associated direction

• could be clockwise or counterclockwise

What is the right hand rule

What is the angular displacement if this exercise began at -5 degrees and ended at 90 degrees ?

inital - final

90 degrees - (-5degrees)

100 degrees (positive direction)

Angular velocity is the rate

angular displacement

What is the angular velocity of the bicep curl if the angle between the upper arm and forearm changed for 8 degrees to 162 degrees and the movement took 3 seconds to complete?

51.33 deg/s 

Average angular velocity represents

the entire movement within the time period

Instantaneous angular velocity represents

two time points that can be infinitesimally close or further apart

Angular acceleration is the rate of

change of angular velocity

• measured deg/s or rad/s

  

You are conducting a cycling study where a subject is rotation the cycle flywheel at 60 revolutions per minute (rpm) and he accelerates 90 rpm over the course of 20 seconds . What is the average angular acceleration