Flashcards in Angular kinetics Deck (21):
what is angular inertia affected by?
- mass of object
- distribution of mass of an object relation to aid of rotation
what is the quantification of angular inertia?
moment of inertia
how does moment of inertia work?
objects are made of matter that resist rotation. the particles located at a distance away from axis of rotation, the harder it is to rotate
moment of inertia equation?
I = mK^2
what is the K term?
Radius of gyration, it is the term for quantifying the distribution of mass
what happens when you try to spin an unfixed object?
it will rotate around its COG, its resistance to rotate will depend units moment of inertia
how can humans manipulate their moment of inertia?
they can change their limb proximities, and distribution of mass therefore moment of inertia will also change.
what happens to the person join the pole vault example?
the person initial wants to increase seethe rotation in the pole vault by extending his body. after that he wants to increase his rotation and decrease rotation of the pole vault so he can get over. he does this by tucking COG underneath his hand placement.
what is momentum?
P = mv; linear sense determined by the mass and velocity
what is angular momentum?
tendency to stay in angular motion
what is angular momentum depended on?
the inertia of object and angular velocity
what is the equation for angular momentum?
L = I x W
what can humans do to alter moment time of inertia?
they can change their arm positioning therefore hanging their angular velocity, which maintaining their angular momentum
what happens when many limbs are rotating?
all limbs will have their own angular momentum. the whole body will have angular momentum is dependant on the sum of all the angular momentum's of the individual limbs
what is N1L for angular momentum?
angular momentum will stay in constant motion unease an eternal net torque is acted upon
what happens when moment of inertia changes?
angular velocity will change to maintain same momentum
the examples of hurdler?
the hurdler leaps forward, swinging left leg forward. in doing that the body will have the tendency to rotate towards the right. the athlete will quickly thrust right leg and arm forward to compensate, disallowing the body to rotate.
N2L: the torque (moment) applied causes what?
causes an angular acceleration of that body proportionate to torque, in the direction of torque exerted, and inversely proportionate to moment of inertia
what happens to the torque when there is a big inertia?
the greater the inertia, the more force needed to make it accelerate.
what is angular impulse?
measure of torque applied over a certain amount of time