Angular Kinetics Flashcards
What is Moment of Inertia and what is its symbol?
Symbol: I
Tendency of a body to resist changes in angular motion
What is the formula for Moment of Inertia?
I = m * (k)^2
Moment of Inertia = Mass * Radius of Gyration ^2
What is mass as it relates to inertia?
Measure of body’s linear inertia
more mass = more inertia
What is inertia
resistance to motion (specifically acceleration)
Centric forces cause what type of motion?
Linear (translational)
Eccentric forces cause which type of motion?
rotational (sometimes linear)
What is torque
turning or rotational effect of an eccentric force
what is another name for torque?
moment of force
Moment arm
What is a moment arm?
perpendicular distance from a forces line of action to the axis of rotation.
Units for Torque
N/m (SI)
Where do torques act?
about an axis of rotation
Longer moment arms require ________force while shorter moment arms require __________ force
less, more
Factors that influence torque
PCSA
Fiber Type
Muscle architecture
velocity
length
nervous system input
PSCA
Physiological Cross Sectional Area
area of a cross section of muscle perpendicular to its fibers
sum of torque at static equilibrium
0
sum of T at dynamic equilibrium
moment of inertia * angular acceleration
Center of Gravity
Imaginary point in the body about which weight is even distributed
Center of Mass
The point about which all mass of the body is evenly distributed
COG while airborne
location of axis of rotation
Axis of rotation
True or False: COG is a fixed point in the body
False COG can move within the body
COG follows what type of path?
Parabolic
Location of COG in children
Higher, larger heads
