Aesthetic Performance Flashcards
A rotating body will continue in a state of uniform
angular motion unless acted upon by?
An external torque
What does external torque produce?
Angular acceleration of a body that is proportional to and in the direction of the torque, and inversely proportional to the moment of inertia of the body
For every torque there is a?
Equal and opposite reaction torque.
Can angular momentum be transferred?
Can be transferred from one body part to another
Does angular momentum change during flight?
Constant during flight (air resistance is negligible) and does not change until contact with an external body like the water in diving
How does the transfer of angular momentum affect planes of motion?
It is what allows it to rotate in different planes.
What are the three axis of rotation?
Frontal axis
Sagittal axis
Vertical axis
What is moment of inertia?
The resistance of a body to rotation.
What is moment of inertia dependant on?
The mass of the object
The distribution of the mass
How can axis of rotation affect moment of inertia?
The closer to the axis of rotation, the smaller the moment of inertia.
Why is the moment of inertia significantly lower when
rotating around the vertical axis?
Because the body is much narrower than it is long – particularly in elite performers. This means that it is easier to pirouette or twist than it is to somersault.
Why do figure skaters speed up before jumping?
The glide before the flight phase allows linear speed to be built up so that forward momentum continues after landing.
What is the importance of the skid during the pivot phase?
The skid helps the skater to rotate about the toe-pick as it assists in converting horizontal velocity to vertical velocity and the angular motion results in a tangential (projectile) velocity at take-off.
An decrease in a divers moment of inertia when moving
from a piked position to a tucked position is due to what?
A change in radius of gyration length
