Angular Motion Flashcards
What is angular motion?
The movement of a body or part of a body in a circular path about an axis of rotation
What force causes angular motion?
An eccentric force, a force applied outside of a bodies centre of mass
What is torque?
The measurement of the turning force applied to a body
What are the principle axes of rotation?
If an eccentric force is applied to a body, it will rotate around one of three principles:
- Longitudinal
- Transverse
- Frontal
What is the longitudinal axis?
The axis that runs from head to toe through the centre of mass, allowing a spinning action
What is a sporting example of a skill on the longitudinal axis?
A full turn in trampolining
What is the transverse axis?
Runs from left to right through the centre of mass
What is a sporting example of a skill on the transverse axis?
An overhead kick in football
What is the frontal axis?
Runs from front to back through the centre of mass
What is a sporting example of a skill on the frontal axis?
Performing actions such as a cartwheel
What are the 3 most important angular motion descriptors?
- Angular velocity
- Moment of inertia
- Angular momentum
What is angular distance?
Total angle a body turns through from start to finish positions when rotating about an axis
What is angular displacement?
The smallest angle between the start and finishing positions of a body rotating about an axis
What is angular speed?
Rate of change in angular distance
What is angular acceleration?
Rate of change in angular velocity
What is a radian?
A measurement that is the angle from the centre of a circle, which intercepts the arc equal in length to the radius of a circle
How many radians is angular motion?
2pi Rads
What is angular velocity?
The rate of change in angular displacement
What is the moment of inertia?
The resistance of a body to change its state of angular motion or rotation
How is the moment of inertia calculated?
Mass x Distribution of mass from the axis of rotation^2
What factors affect the size of inertia?
The distribution of mass and the mass of the body
What is angular momentum?
The quantity of angular motion possessed by a body
How is angular momentum calculated?
What is its unit?
Moment of inertia x angular velocity
KgM^2rad/s
What is the conservation of angular momentum?
Once created it is constant. If inertia increases, angular velocity must decrease (vice versa)
Define the conservation of angular momentum?
“A rotating body will continue to turn about its axis of rotation with constant angular momentum unless acted on by an eccentric force”
