Week 23 - Linear Kinematics

Question 1

what is a video ?

Answer 1

a 2D representation of a 3D scene

Question 2

what are the most important parameters for video analysis ?

Answer 2

• sampling rate
• shutter speed
• aperture

Question 3

what is sampling rate ?

Answer 3

frames per second

Question 4

what is the standard frame rate ?

Answer 4

25 Hz

Question 5

what is shutter speed ?

Answer 5

how long the sensor is ‘open’ and exposed to light

Question 6

what are the risks of a low shutter speed ?

Answer 6

blurred image if the movement is fast

Question 7

what are the risks of a high shutter speed ?

Answer 7

dark images

Question 8

what is aperture ?

Answer 8

influences amount of light and depth of field

Question 9

what is a large aperture ?

Answer 9

• much light

- smaller f-stop

Question 10

what is a small aperture ?

Answer 10

• less light
• larger f-stop
• better depth of field

Question 11

what is the sampling rate for walking ?

Answer 11

25 - 50 Hz

Question 12

what is the sampling rate for running ?

Answer 12

50 - 100 Hz

Question 13

what is the sampling rate for a football kick ?

Answer 13

100 - 200 Hz

Question 14

what is the sampling rate for tennis serve ?

Answer 14

200 - 500 Hz

Question 15

what is perspective error ?

Answer 15

the error caused in the position of an object when the viewing angle is not perpendicular to the object

Question 16

define rectilinear

Answer 16

translation occurs along a straight line

Question 17

define curvilinear

Answer 17

translation occurs along a curved line

Question 18

define rotation

Answer 18

all parts of the body move through the same angle in the same time

Question 19

define scalar

Answer 19

describes only in terms of MAGNITUDE

Question 20

define vector

Answer 20

describes in terms of MAGNITUDE, DIRECTION and SENSE

Question 21

define position

Answer 21

location in space relative to a reference

Question 22

define trajectory

Answer 22

the path followed by the object in motion

Question 23

define distance

Answer 23

length of a trajectory path

Question 24

define displacement

Answer 24

change in position between two points in time

Question 25

what is the symbol for displacement ?

Answer 25

s

Question 26

what is displacement measure in ?

Answer 26

m

Question 27

define velocity

Answer 27

rate of change in position between two points in time

Question 28

what is the symbol for displacement ?

Answer 28

v

Question 29

what is velocity measured in ?

Answer 29

m/s

Question 30

how do you calculate displacement ?

Answer 30

s = v x change in t

Question 31

how do you calculate velocity ?

Answer 31

v = s / change in t

Question 32

how do you calculate acceleration ?

Answer 32

a = Vf - Vi / change in t

Question 33

what is the symbol for acceleration ?

Answer 33

a

Question 34

what is acceleration measured in ?

Answer 34

m/s^2