BIOMECH Flashcards
(15 cards)
momentum
measure of how hard it is to stop a moving object
=mass * velocity
Higher momentum = harder to change movement of an object
Total momentum is conserved before and after an impact
impulse
Total effect (change in momentum) of a force over a time
= force * time
reducing/ increasing momentum
flatten the curve
reduction: more time = reduction of peak force
increasing: force over longer period of time = f in contact for longer = higher I
moment of inertia
a body’s resistance ot its state of angular/rotational motion
how hard it is to change how fast it rotates
= mass * distance from axis of rotation
angular momentum
Angular momentum = MoI * Angular vel
coefficient of restitution
bounciness of the relationship between two objects
CoR 1= elastic
CoR 0 = inelastic
impacts to CoR
Increased temp: higher CoR
Increased vel before = decreased CoR
greater compression of the ball
Equipment + surfaces
depends on the thing: newer ball = higher CoR
harder = usually CoR
laminar flow**
smooth
boundary layer
thin layer of air surrounding ball
turbulent flow **
rough
boundary layer separation**
where boundary layer breaks away from ball
earlier breaks away = ^ pressure gradient between front + back of ball
(early separation creates a larger wake of low-pressure fluid behind the object)
= less drag
factors affecting boundary layer separation point
Velocity: lower vel = boundary layer clings to surface, separation towards rear = less drag
Surface roughness: rough surface = turbulent boundary layer =less drag
Shape: oval = separation point further back = less drag
fluid resistance
Resistance to motion of a body in a fluid due to forces of friction being exerted between the body and the fluid
greater distance = higher transfer of energy from object to fluid
types of drag
form drag
surface drag
wave drag
