Biomechanics - Angular motion Flashcards
Define angular motion
Movement of a body in a circular path around an axis of rotation
Define eccentric force
Force applied outside the centre of mass resulting an angular motion.
What is the principal axis of rotation
Imaginary line through the centre of mass which a body rotates longitudinal, transverse and frontal axis
Define angular velocity
The rate of change in angular displacement measured in radians per seconds.
How do you calculate angular velocity
angular displacement / time taken
Define moment of inertia
The resistance of a body to change its state of angular motion or rotation. Measured in kgm2
How do you calculate moment of inertia
mass x distribution of the mass from the axis of rotation 2(squared)
State and explain two factor that affect moment of inertia
Mass - greater the mass the greater the moment of inertia. Low mass decreases moment of inertia and resistance to change
Distribution of mass - further the mass moves from the axis, the greater the moment of inertia. Tucked position will lower it.
Define angular momentum
The quantity of angular motion possessed by a body. Measured in kgm2rad/s
Formula for calculating angular momentum
moment of inertia x angular velocity
What is linear motion
Movement of a body in a straight line or curved line where all parts move the same direction over the same time
Define direct force
A force applied through the centre if mass resulting in linear motion
What is centre of mass
where a body is balanced in all directions, which weight appears to act.
