Lecture 1-6 Flashcards
1
Q
What does kinesis and logia MEAN
A
kinesis = movement logia = branch of learning
2
Q
What does biology, mechanics and biomechanics mean?
A
biology = study of living organisms
mechanics = analysis of force and its effects
biomechanics = the study of force and their effects on living systems
3
Q
what is rigid force mechanics
A
refers to the application of force to a system that does not deform/change shape
4
Q
what is deformable body mechanics
A
refers to the application of force to a system that deforms/changes shape
5
Q
what kind of mechanics would the bending of a wire be? where it goes back to the original shape?
A
deformable body mechanics
6
Q
what is fluid mechanics
A
self explanatory. water
7
Q
what is relativist mechanics
A
relativistic refers to something that changes location sporadically. were not looking at this
8
Q
what is quantum mechanics
A
refers to the examination of really small things
9
Q
how are kinematics and kinetics different?
A
kinematics examines movement, describing motion over space and time. kinetics examines FORCES, and studies the motion that results from it
10
Q
what is static vs dynamic
A
static = unchanging velocity. movement and non movement are both static, but they have to have zero acceleration
11
Q
should you write 0 or 0.0
A
0.0
12
Q
what is length measured in
A
metres
13
Q
what is time measured in
A
seconds
14
Q
what is inertia
A
resistance to change, measured in kg!
15
Q
what is mass?
A
a quantity of matter
16
Q
how is mass, force and weight different
A
mass is a quantity of matter, and weight is a type of force, where w = ma
17
Q
What do scales measure?
A
WEIGHT. not mass. w = mg. scales measure with gravity so it cannot be onlly mass.
18
Q
define force
A
force: a push or pull that ATTEMPTS to create motion change
19
Q
What is wrong with this sentence: Force is a push or pull that creates a change in motion
A
it does not always create!!! sometimes it only attempts
20
Q
What does force depend upon?
A
- size of force
- point of application
- relative position (bolted down vs chair on wheels)
21
Q
Do forces act singly?
A
No! Forces come in pairs, where they match each other but are oppositely directed.
22
Q
define reaction force
A
reaction force: the force that opposes or reacts to an inflicted force, equal in magnitude. these create movement
23
Q
What is the standard unit for force?
A
newton
24
Q
what is one newton equal to?
A
N = the force required to accelerate 1kg of mass 1m/s^2
25
What is the formula for force
F = mass x acceleration
26
what are the units for momentum
kgm/s
27
What is meant by internal vs external forces
internal forces = act within the system, like muscles pulling on tendons, or bones pushing on cartilage
external forces = act on an object as a result of its interaction with surroundings
28
what is an example of contact and non contact external forces?
contact forces occur between objects in contact. either solids, fluids or air
non contact forces occur even if objects are not touching. like gravity, magnetic forces, or electrical forces
29
what is the force of gravity equal to
-9.81m/s^2
30
what is the formula for weight
w = ma
31
what are dynamographs?
they measure and record forces and pressure.
32
what are strain gauges in dynamographs?
They are often metal foils/tubules that measure the strain on a system (tension)
33
what are load cells in dynamographs
It is a transducer that turns force into some sort of signal, often electrical
34
what are force platforms
load cells are often put with these, they are instruments that measure ground reaction forces generated by a body standing or moving across the platform
35
when walking or running, how does GRF of a force platform change with body weight?
walking multiplies body weight by 1-1.2 times
running multiplies body weight by 3-5 times
36
what is friction
friction: a force created by the physical contact between two systems
37
is is possible to have zero friction?
no. no two systems are perfectly smooth
38
is it easier to move an object if it is on its back or end?
neither! The friction would be the same
39
what is the formula for friction?
f = coefficient of friction x normal contact force
40
what are the two types of friction
static: two objects in contact, not in motion
dynamic: two objects in contact and motion
41
Is rotation considered linear or angular?
angular
42
Is translation considered linear or angular?
linear
43
Is position change considered linear or angular?
linear
44
Is orientation change considered linear or angular?
angular
45
Is spinning around a fixed axis considered linear or angular?
angular
46
what is general motion?
a combo of both linear and angular motion
47
What is linear motion
linear motion: type of motion that occurs when all points on a body/object move the same distance, direction, and at the same time
48
what are the types of linear motion?
1. rectilinear motion: movement along a straight line
2. curvilinear motion: movement along a curved line
49
linear kinematics is the _____________ of movement
description
50
what is the cartesian coordinate system?
2D system of looking at position changes, where up and right are positive. Upper right is quad #1, upper left is 2, lower left is 3, and lower right is 4
51
what is the difference between scalar and vector quantity?
scalar quantity looks at distance/speed. cares about total length of the path
vector quantity looks at displacement/velocity. cares about length of line between two points
52
define pace
pace: (noun) a person's manner of walking or running, OR (verb) the measure of time with respect do distance travelled
53
what is pace the opposite of?
speed
54
what is the opposite of speed?
pace
55
what is the formula for pace
pace = change in time / change in distance
56
What is the formula for acceleration
a = change in velocity / change in time
57
what are the base units for acceleration?
m/s^2
58
Replicate the graph that looks at direction of motion, state of motion and direction of push, and how this changes with acceleration (speeding up/slowing down or unchanging)
59
what is a projectile
projectile: a body projected into the air or dropped from a height, moving through air unassisted
60
what forces influence projectile movement?
air resistance and gravity
61
is the force of gravity constant or changing?
constant! AKA uniform acceleration
62
what are the main forces acting on vertical projectile components and horizontal?
vertical = gravity
horizontal = air resistance
63
explain why projectiles thrown upwards end up falling back down
as the speed of the system increases, upward air resistance acts on the system until it equals the gravitational pull, at which point the object stops accelerating and starts to fall
64
what is terminal velocity
the constant speed acheived by objects in free fall
65
what is terminal velocity affected by (with falling)
Terminal velocity is affected by projected area! If a sky diver free falls, they fall slower than if their limbs were extended?
66
what is the apex?
it is the highest point in a projectile's path, AKA where acceleration is 0
67
what is trajectory
trajectory: path travelled
68
what are the types of trajectory? What goals do they correspond with>
1. vertical trajectory = goal of max height
2. oblique trajectory = goal of translation and max flight time
3. horizontal trajectory = minimal flight time
69
what is range
range: max horizontal displacement
70
what is the range release angle theory?
idk
45 degrees if take off height = landing height
> 45 degrees if take off height < landing height
< 45 degrees if take off height > landing height
71
what is the law of constant acceleration
idk - states that the force of gravity is constant so the acceleration of the system will not change
72
what are the formulas that correspond to the law of constant acceleration?
v2 = v1 + at
v2^2 = v1^2 + 2ad
d = v1t + (1/2)at^2
73
If a bullet fired horizontall from a gun, and another bullet dropped from the same height, which would hit the ground first?
if they are released from the same position, they would still fall from the exact same height despite any horizontal movement, because horizontal movement is irrelevant to vertical movement
74
kinesiology examines movement from the. __ to the ___ level
cellular, societal
75
what is terminal velocity?
the constant speed that an object reaches during free fall
76
should know the graph for measuring forces, where it looks at vertical jumps and the force changes that occur throughout that movement
lec 3 slide 19
77
is static friction two objects in a constant state of motion, or two objects not in motion
not in motion. kinetic friction deals with constant states, as long as there is movement
78
What measurements do we look at for linear kinematics?
speed, distance and direction (idk if there are more)
79
What is velocity and acceleration in a static state?
no acceleration, v2 = v1
80
What are some kinematic terms?
displacement, velocity and acceleration
81
does kinematics look at mass?
NO! it looks at geometric aspects, not mass and not forces.
Looks at formulas like
v2=v1+at
v2^2=v1^2t+1/2at^2
d= v1t+2ad?
82
what type of motion is a change in position
linear
83
Why might running in high heels be better for you than runners?
high heels shift the force to the ball of your foot, so there is less force on your ankles and knees. by adjusting the force (kinetics), you can change your running (kinematics)
84
draw the graph for static and kinetic friction, with its relation to applied force
*in the pics that tiffani sent me*
85
how are speed and velocity different?
- both kinematic values, both measure how fast or slow an object is
- speed looks at distance over time, and is scalar
- velocity looks at displacement over time, and is a vector
86
what is radial acceleration
radial acceleration: the acceleration of an object towards the centre of a circular path
87
define tangential acceleration
tangential acceleration: the rate at which the velocity of an object in circular motion changes
88
how are radial and tangential acceleration different?
radial acceleration directs to the centre of circular motion, tangential acceleration changes linear velocity of circular motion
89
what happens if a system travels with both radial and tangential acceleration
it will translate and rotate. radial acceleration will cause rotation. tangential will cause translation?
90
what happens to a joint if the relative angle increases?
extension
91
what happens to a joint if the joint angle decreases
flexion
92
define a lever
lever: a rigid body that can be made to rotate around a fixed axis by an applied force.
92
what happens if a joint angle increases past the anatomical position
hyperextension
93
what thing magnifies the effect of levers
muscles
94
define centre of gravity
centre of gravity: the average location of all the weight of an object, where mass is equally dispersed in all directions
95
why is it important to know centre of gravity?
Applying force at the centre of gravity is best to attempt motion
96
how can we tell how much time has elapsed in a time frame?
the interval of frames x recording rate (hz) = time
97
What is the formula for scaling factor
actual distance / measured distance
98
define tangential velocity
tangential velocity: linear velocity of an object moving in a circular motion
99
how is tangential velocity and linear velocity different
tangential velocity only occurs if an object is moving, whereas linear velocity occurs with any object
100
define angular motion
angular motion: rotation around an axis or fixed point
101
change in orientation is what kind of movement
angular
102
what are the terms of linear movement
- translation
- change position
- move in the same direction
103
what are the terms in angular movement
- orientation
- rotation
- spin
