KINES 162 Exam One (NP)

Goals of Physics in Sport and Exercise

Performance improvement

technique improvement

equipment improvement

technique improvement

injury prevention and rehabilitation

Kinematics

Deals with the description of motion without considering the forces that cause motion.

Kinetics

Deals with the relationship between the motion of bodies and the forces acting upon them

3 Main Measurements

length/distance, time, mass/inertia

length & distance

Time

Highly valuable metric in sports, exercise, physical activity, research

basic aspect for motion

Mass & Inertia

nertia is the property of an object to resist change in its motion

mass is the measurement of inertia

Basic SI Units

Length = meter

Time = Sec

Mass = kilograms

Scalar

Magnitude only

mass, volume, density, distance & speed

Vector

magnitude & direction, orientation, point of application

displacement

force

velocity & acceleration

Components of Projectile Motion (3)

time of flight, peak height, horizontal displacement

horizontal motion

v = vf = vi and a = 0

velocity is constant and in a straight line

horizontal path traveled (if starting position is known)

xf = xi + vchangeintime

Vertical motion

any projectile thrown straight up in the air

has no forward motion

vertical position equation

y = yi + vichangeintime + 1/2g(changeintime)²

Maximum Height (high jump)

90 degrees projection or >45 degrees

Minimizing Time of flight

45 degrees or less (soccer penalty kick, baseball pitch, volleyball spike)

Maximize horizontal displacement

slightly below 45 degrees (long jump, shotput)

acceleration

change of velocity/change in time

mass

measured in kg does not account for gravity

weight

measured in newton and accounts for gravity

how can you analyze kinematic

motion capture and coordinate system

kinematic analysis procduces

temporal variables

distance

total path traveled

displacement

shortest path between start and end point

pythagorean theorem

helps measures displacement

speed

distance/time

velocity

displacement/time

running speed

stride length x stride rate

relationship between stride length and rate

as we increase running velocity we tend to increase stride length faster than we increase stride rate, eventually stride length reaches plateau as they have reached their limit therefore the person has to increase stride rate

derivtive

rate at which a value changes with respect to another value

if initial height = final height

displacement is determined by velocity (long jump)

Relative angle

angle between two moving segments

absolute

angle of single segment

movement in sagittal plane occurs

about the mediolateral axis

movement in the frontal plane occurs

about the anteroposterior axis

movement in the transverse plane occurs

about the longitudinal axis

right hand rule

determines direction of rotation

thumb up

positive and counterclockwise

thumb down

negative and clockwise

revolutions

1 = 360 degrees

1 radian

57.3 degrees

angular distance

total of all angular changes measured following path

angular displacement

difference between initial and finale position of rotating object

angular to linear relationship (soccer)

change angular velocity

angular to linear relationship (golf)

change radius