biochem exam 1

kinematics

description/characteristics of motion

examples of kinematics

displacement, velocity, acceleration

position

objects location in space relative to another object

distance

measured along total path traveled

diplacement

change from final and initial position

vector

magnitude and direction

vector example

velocity

speed

distance traveled/time

Is speed scalar or vector?

scalar

velocity

displacement/time

Is velocity scalar or vector?

vector

acceleration

change in velocity/cange in time

Is acceleration a scalar or vector quantity?

vector

instantaneous

velocity/acceleration at a particular instant in time

average

velocity/acceleration over an entire movement

rules of PVA

peaks become 0s, no slope = no change, inflections become peaks

angular motion

rotation around central line or point

t or f: in angular motion, different regions of the body all move at the same distance in same amount of time

false, they do not move at the same distance

angles

composed of 2 lines that intersect at a vertex

absolute angles

ang;e that describes segments orientation in space

Absolute Angles (segment angles)

The angle between a segment and the right horizontal of the distal end.

relative angle (joint angle)

angle between two segments

where do you place coordinate system of absolute angles

distal end point

goniometer

used by clinician for direct measurement of relative angles on a patient

angular distance

sum of all angular changes undergone by a rotating body

angular displacement

difference in initial and final positions of the moving body

angular speed

angular distance/time

what does σ represent in angular speed equation

angular speed

what does ϕ represent in angular speed equation

angular distance

angular velocity

change in angular position (displacement)/change in time

what does ω represent in angular velocity equation

angular velocity

what does θ represent in angular velocity equation

angular displacement

angular acceleration

change in angular velocity/time

what does α represent in angular acceleration equation

angular acceleration

what does ω represent in angular acceleration equation

angular velocity

in angular motion, moving counterclockwise is

positive rotation

in angular motion, moving clockwise is

negative rotation

radius of rotation

distance from axis of rotation to a point of interest on a rotating body

the larger the radius of rotation

the greater the linear displacement

what is the s in radius of rotation equation

distance traveled

what is the r in radius of rotation equation

points radius of rotation

what is the θ in radius of rotation equation

angular displacement through which rotating body moves

projectile

body in free fall that is subject only to forces of gravity and air resistance

what component is affected by gravity, vertical or horizontal

vertical

which component related to distance the projectile travels

horizontal

which component related to maximum height the projectile travels

vertical

what is the velocity of an object at the peak of a projectile

0

trajectory

the flight path of a projectile

how is trajectory displayed

parabolic curve

what are the 3 factors that influence trajectory

angle of protection, projection speed, height of projection

projection angle

direction of body/object is projected with respect to the horizontal

what if angle is perfectly vertical, what will happen to trajectory

trajectory is vertical

what if angle is perfectly horizontal, what will happen to trajectory

trajectory is 1/2 of parabola

what if angle is oblique, what will happen to trajectory

parabolic

projection speed

the magnitude of projection velocity

what does projection speed determine

length/size of projectile's trajectory

objects projected vertically, initial speed determines

height of trajectory apex

objects projected at oblique angles

speed determines the height and length of trajectory

vertical velocity

reduced by gravity, determines height of apex, affects time to reach apex

horizontal velocity

constant throughout flight

greater the velocity at takeoff

higher the jump - greater amount of time jumper is in air

projection height

difference between projection height and landing height

projection velocity and angle of projection are constant

longer flight time and greater horizontal displacement of projectile

projectile released and land at same height

time up to apex = time down from apex

projectile released from point higher than surface on which it lands

time up to apex less than time down from apex

projectile released from point below surface on which it lands

time up to apex greater than time down from apex

if profection height is 0, the angle of projection that produces maximum horizontal displacement is

45

biomechanics

application of mechanical principles in study of living organisms

statics

branch of mechanics dealing with systems in a constant state of motion

dynamics

branch of mechanics dealing with systems subject to acceleration

kinetics

examine forces acting on a system

qualitative

nonnumeric description of quality

quantitative

involving the use of numbers

2 types of motion

linear and angular

linear motion

movement along straight path

3 cardinal planes

sagittal, frontal, transverse

sagittal plane movements

flexion, extension, hyperextension

frontal plane movements

abduction, adduction, inversion, eversion

transverse plane movements

rotation, supination/pronation

stress

force applied to deform a structure

strain

resulting deformation

stress is

force per unit area

stress formula

𝜎 = F/a

strain is

ration of the change in length of a structure and its initial height

strain equation

𝜀=Δ𝐿/𝐿

elastic modulus

stiffness of material

yield point

slope decreases as force is increased

elastic region

region before yield point

plastic region

region after yeild point

failure

occur when stress is applied beyond plastic region

residual strain

difference between original length of material and resting length

elastic material

applied load is removed, material returns back to original length

viscoelastic materials

magnitude of stress being dependent on rate of loading

function of skeleton

support, attachment sites, leverage, protection, storage, blood cell formation

what is stiffness determined by

slope of curve in elastic region

difference between cancellous and cortical bone contribute to

anisotropy of bone

cancellous bone provides

bending and strength

cortical bone provides

significant compressive strength

articular cartilage

allows movement between 2 bones with minimal friction

fibrocartilage

improves the fit between bones