angular motion Flashcards
What is angular motion
Movement of a body or part of a body in a circular path about an axis of rotation
What is an eccentric force
A force applied outside the CoM,resulting in angular motion
What is torque
A measurement of the turning(rotational or eccentric) force applied to a body
What is the principle of rotation
An imaginary line that passes through the CoM about which a body rotates,longitudinal,transverse and frontal axis
What is the longitudinal axis
Runs from head to toes through CoM
What is the transverse axis
Runs from left to right through CoM
What is the frontal axis
Runs from front to back through CoM
What axis does sagittal plane go with
transverse axis
-E.g. walking,squatting,overhead pass
What axis does frontal plane go with
frontal axis
-e.g. start jumps and side bends
What axis does transverse plane go with
Longitudinal axis
-E.g. hips in golf swing,shoulder in throwing
Example in longitudinal axis
spin,pirouette or full turn in trampolining
Example of transverse axis
Sommersault
Example of frontal axis
Cartwheels
What is the moment of inertia(MOI)
A body’s resistance to change it’s state of rotation
-The greater the mass of the body,the greater the MOI
What happens if MOI is high
If MOI is high,resistance to rotation is also high,therefore angular velocity is low:the rate of spin is slow
What happens if MOI is low
If MOI is low,resistance to rotation is also low,therefore angular velocity is high and the rate of spin is fast
What is the conservation of angular motion
Angular motion is a conserved quantity which remains constant unless an external force or torque is applied
What is the angular analogue of newtons first law of motion
The angular equivalent of newtons first law of motion,which states a rotating body will continue to turn about its axis of rotation with constant angular momentum unless acted upon by an eccentric force or external torque
What is angular velocity
The rate of change in angular displacement simply rate of rotation
Equation for angular velocity
angular displacement/time taken
-Rad/s
What is the moment of inertia
Resistance of a body to change its state of angular rotation
MOI equation
- sum of M x r squared
-Kgm squared
Angular momentum equation
MOI x angular velocity
-kgm2rad/s
