Biomechanical principles, levers and the use of technology (1.3a) Flashcards
1
Q
newtons first law is…
A
the law of inertia
2
Q
newtons second law is…
A
the law of acceleration
3
Q
newtons third law is…
A
the law of reaction
4
Q
define the law of inertia
A
a body continues in a state of rest or uniform velocity unless acted on by an external or unbalanced force
5
Q
define the law of acceleration
A
a body’s rate of change in momentum is proportional to the size of force applied and acts in the same direction as the force applied
6
Q
define the law of reaction
A
for every action there is an equal and opposite reaction
7
Q
define velocity
A
the rate of change in displacement
8
Q
velocity is measured in….
A
m/s
9
Q
velocity =
A
displacement / time taken
10
Q
define momentum
A
the quantity of motion possessed by a moving body
11
Q
momentum is measured in…
A
kgm/s
12
Q
momentum =
A
mass x velocity
13
Q
define acceleration
A
the rate of change in velocity
14
Q
acceleration =
A
(final velocity - initial velocity) / time
15
Q
acceleration is measured in…
A
m/s/s
16
Q
define force
A
a push or a pull that alters the state of motion of a body
17
Q
force is measured in…
A
N
18
Q
force =
A
mass x acceleration
19
Q
the two types of force are…
A
internal force
external force
20
Q
force has 5 effects, which are….
A
- create motion
- accelerate a body
- decelerate a body
- change the direction of a body
- change the shape of a body
21
Q
if net force is zero..
A
there is no change in motion as forces are balanced
22
Q
define net force
A
the sum of all forces acting on a body
23
Q
the external force acting on a body can be split into two different forces that are…
A
horizontal force
vertical force
24
Q
the vertical forces that act on a body are….
A
weight and reaction
25
define weight
the gravitational pull that the earth exerts on a body
26
weight =
mass x acceleration due to gravity
27
weight is measured in....
N
28
define reaction
the equal and opposite force exerted by the body in response to the action force placed upon it
29
reaction force is measured in...
N
30
the horizontal forces that act on a body are...
friction
air resistance `
31
define friction
the force that opposes the motion of two surfaces in contact
32
what 4 factors affect friction?
roughness of ground surface
roughness of contact surface
temperature
size of normal reaction
33
practical example of roughness of ground surface affecting friction
athletes run on rough, rubber tracks
34
practical example of roughness of contact surface affecting friction
athletes wearing spiked shoes
35
practical example of temperature affecting friction
F1 drivers have a warm up lap to increase tire temperature
36
practical example of size of normal reaction affecting friction
shot putter have a high mass creates a greater opposite reaction force allowing greater friction in throwing circle `
37
define air resistance
the force that opposes the direction of motion of a body through the air
38
what 4 factors affect air resistance?
velocity
shape
frontal cross sectional area
smoothness of surface ``
39
practical example of velocity affecting air resistance
the greater the velocity of a cyclist the greater the force of AR opposing their motiom
40
practical example of shape affecting air resistance
cyclists wearing a teardrop helmet to minimise AR
41
practical example of frontal cross sectional area affecting air resistance
the low crouched position of a downhill skier reduces AR
42
practical example of smoothness of surface affecting air resistance
increased smoothness from lycra suits reduces AR
43
define centre of mass
the point at which an object or body is balanced in all directions
44
define stability
the ability of the body to resist motion and return to the original position without damage
45
what 4 factors that affect stability?
mass of the body
height of the centre of mass
base of support
line of gravity
46
how does mass of the body affect stability?
the greater the mass, the greater the inertia and therefore the stability
47
how does height of the centre of mass affect stability?
the lower the centre of mass, the greater the stability
48
how does base of support affect stability?
the greater the size of the base of support, the greater the stability
49
how does line of gravity affect stability?
the more central the lie of gravity to the base of support the greater the stability
50
the 2 main functions of a lever system are....
to generate muscular effort to overcome a given load
to increase the speed of a given movement
51
the 4 components of a lever system are...
lever
fulcrum
effort
load
52
what is the order of components in a first class lever?
load fulcrum effort
(LFE)
53
what is the order of components in a second class lever?
effort load fulcrum
(ELF)
54
what is the order of components in a third class lever?
fulcrum effort load
(FEL)
55
an example of a first class lever being used in the body is
extension of the neck when preparing to header a football
56
an example of a second class lever being used in the body is
ball of the foot in the take-off phase of a high jump `
57
an example of a third class lever being used in the body is
flexion of the elbow during a biceps curl
58
the effort arm is...
the distance between the fulcrum and the effort
59
the load arm is...
the distance between the load and fulcrum
60
a lever has mechanical advantage when....
its effort arm is longer than its load arm so a larger load can be moved with a relatively small effort
61
which type of lever in the body has mechanical advantage?
second
62
a lever has mechanical disadvantage when....
the load arm is greater than the effort arm so a large effort is needed to move a relatively small load
63
which type of lever in the body has mechanical disadvantage?
third
64
define limb kinematics
study of movement in relation to time and space
65
define force plates
ground reaction forces are measured in lab conditions using force plates
66
define wind tunnels
steel frame building containing wide fans where artificial wind is produced
67
how is limb kinematics used?
3D or optical motion analysis records an athlete doing a sporting action, allowing the evaluation of efficiency of movement
68
how are force plates used?
athletes balance, run and jump on the plates which assesses the size and direction of forces acting on the athlete, acceleration rates, work and power output
69
how are wind tunnels used?
technology is used to develop the drag reduction system. objects can be tested for aerodynamic efficiency
70
how can limb kinematics be used to optomise an athletes performance?
data produced can be used by coaches to improve performance and technique of an athlete
71
how can force plates be used to optomise an athletes performance?
used for sports biomechanics assessment, gait analysis, balance rehabilitation and physical therapy
72
how can wind tunnels be used to optomise an athletes performance?
engineers study the flow of air around an objcet, the aim is to improve the air flow around an object to increase lift or decrease drag
