test 2 Flashcards
units for angular kinematics
degrees or radiant
formula for angular kinematics( velocity)
0 final- 0initial / change in time the 0 is pheta
measured in - deg/s or rad/s
what is complex kinematics
linear and angular combined, multi segment kinematics
linear and angular combined is defined as what
at the end of a rotating end there is a linear component
tangential velocity
tangent to the curve but kicks out anytime
what is the strange w stand for
angular velocity
what is a force by definition
a push or a pull
what are the four behavioral properties of a force
magnitude, direction, point of application, line of action
line of action
a line that goes infinitely through the course of action
external forces are considered
external forces are considered gravity(9.81m/s2), fluid resistance(aerodynamics), friction, contact with another surface or object
internal forces are considered
muscle and joint force, friction
work is what mathematically
force times distance or newton times meters
force is what unit
newtons
distance is what unit
meters
external work examples
95 lbs is how many newtons
95 divided by 2.21 to get kg and then multiply by 9.81 m/s2
or 1 lbs is 4.448 n can do 95lb times 4.448 n
you would take the newton found and multiply by the meters found or distance
power is calculated as
work divided by time
what is more important force or distance
the rate at which you can do work is athletically far more important the amount of work you can do
Velocity is calculated as (m/s)
Distance by time
Momentum is calculated as (kg.m/s)
Kg times m/s
Ke or energy is calculated as (j)
1(/2) mass velocity squared
Types of forces
compressive, tensile, torsional, shearing
compressive force is what
makes objects shorter and wider
tensile force is what
distraction, traction force
torsional force is what
rotational force
shearing force is what
a combination of sharing and torsional force
what is a kinetic chain
forces that are transmitted through limbs that are connected
classes of levers
1st class
2nd class
3rd class
2nd class
same side of the axis of rotation and the applied force is further away then the resistance force change——fr——-fa
1st class
applied force and resistant forces are on opposite sides of the axis
fr——–change——–fa
movement arm, lever arm, torque arm are what
arm means length, “perpendicular distance from the axis of rotation to the point of application of the force in question”
what is better a longer or shorter movement arm
longer
3rd class lever is what
applied forces and resistance forces are on the same side of the axis but the resistance force has a longer movement arm
what do the majority of the muscles in the body operate at
a mechanical disadvantage for force but good for speed and agility
know the classes of levers and the examples of each
no second class lever**
mechanical advantage/disadvantage equation
mechanical advantage= effort arm/resistance arm
torque or moment equation
force times distance(mechanical distance) or newton times meters
what is assumed for moment/torque
proximal moment or torque is in the positive direction
elbow flexor moment
positive moment at the elbow is a elbow flexor moment
adj is what angle
top one
hyp is what angle
bottom one
opp is what angle
to the right
how do moment and resistance forces move
moment arm for the resistance forces and effort force change instantaneously depending on joint angle
work energy theorem is what
work = change in energy
types of energy
kinetic, potential, thermal
kinetic energy is what
some type of energy associated as motion( tke- translational kinetic energy, rke- rotational kinetic energy)
rke is calculated as
1/2intertia*omega2
tke is calculated as
1/2mv2
something that has alot of inertia has what
resists change
potential energy is what
potential for an object to do work based on its location in space
potential energy is what calculated
massgravityhigh above the ground
stored elastic energy is what
energy associated with something elastic (rubberband)
if the force of the resistance is greater then the force of the muscles what kind of energy do you get
ecentric
if the force of the resistance is less then the force of the muscles what kind of contraction do you get
concentric
if the force of the resistance is greater then the force of the muscles what kind of contraction do you get
eccentric
if the force of the resistance and the force of the muscles are equal what kind of contraction do you get
isometric