friction Flashcards
pros and cons of embedded force plate
-accurate and reliable
-high sampling frequency and resolution
-expensive
-ecologicial validity - can’t recreate outside activity
pro and con of portable force platform
-cheaper
-slightly worse reliability and resolution
triaxial accelerometer
need to know what ur using it for in order to assess whether it is reliable and valid
accelerometer position
-can monitor closer to site of interest
-cheaper than lab based equip
-battery life
-is it valid for intended purpose
fluid dynamics
is the friction you get due to an object moving throughhhh something
4 letters of drag force equation and meaning
p = density of fluid
v2 = relative velocity
Cd = drag coefficient
a = surface area
relative velocity
-needs to take head and tail wind into account
-if doubled, will quadruple drag force because it is squared
3 ways to reduce drag
-reduce frontal surface area of object
-more streamlined shape
-slower relative velocity
the higher the drag coefficient,
the more drag force there is
laminar flow ->
air flows smoothly over object
little disruption to fluid
turbulent flow ->
slows objects
causes more friction
define friction
a force that acts in opposition to the movement of one surface over another
friction equation
friction = coefficient of friction x normal force
static friction means
no motion
sliding friction means
sliding motion
