Section 11: Biomechanical movement Flashcards

1
Q

What is a scalar quantity?

A

when measurements are only described in terms of size or magnitude e.g. mass, distance and speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is a vector quantity?

A

when measurements are described in terms of magnitude and direction e.g. weight, displacement, acceleration, velocity, momentum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Definition of mass

A

mass is the quantity of matter the body possesses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Definition of distance

A

distance is measured in metres and is the path a body takes as it moves from the starting to the finishing position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Definition of displacement

A

displacement is measured in metres and is the shortest route in a straight line between the starting and finishing position

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Definition of speed

A

speed is a measurement in metres/seconds of the body’s movement per unit of time with no reference to direction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Definition of velocity

A

velocity is measured in metres per second and is the rate of change of displacement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Definition of acceleration

A

acceleration is measured in m/s2 and is the rate of change of velocity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Equation for momentum

A

momentum (kgm/s)= mass (kg) x velocity (m/s)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is an internal and external force?

A

internal force= generated by the skeletal muscles

external force= comes from outside the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Definition of weight

A

weight is the gravitational force exerted on an object

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Equation for weight

A

weight = mass (kg) x gravity (9.8)

measured in newtons, N

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a reaction force?

A

a reaction force occurs when two bodies are in contact with one another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is friction?

A

friction occurs when two or more bodies are in contact with one another

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is air resistance?

A

air resistance is a force that acts in the opposite direction to the motion of a body travelling through the air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is impulse? (given as an equation)

A

impulse = force x time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is net imupulse?

A

net impulse is a combination of positive and negative impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is angular motion?

A

angular motion is movement around a fixed point

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a torque?

A

the rotational consequence of a force (a turning force)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is radian?

A

the unit of measurement for angles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is angular displacement?

A

the smallest change in angle between the start and finish point of a rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is angular velocity?

A

the rate of change of angular displacement OR angular displacement over time taken

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is angular acceleration?

A

the rate of change of angular velocity OR change in angular velocity over time

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is moment of inertia?

A

resistance of a body to angular motion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is angular momentum?

A

the quantity of rotation a body possesses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is horizontal displacement?

A

the shortest distance from the starting point to the finishing point in a parallel line to the ground

27
Q

What 3 factors determine the horizontal displacement of a projectile?

A
  • angle of release
  • speed of release
  • height of release
28
Q

What is the optimum angle of release?

A

angle between the horizontal axis and the direction of the projectile at release

29
Q

What is the optimum angle of release if the release height and landing height are equal?

A

45 degrees

30
Q

What is the optimum angle of release if the release height is below the landing height?

A

greater than 45 degrees

>45

31
Q

What is the optimum angle of release if the release height is higher than the landing height?

A

les than 45 degrees
<45
(for a world class shot-putter it is between 26-38 degrees)

32
Q

What is a parabola?

A

a curve with a matching left- and right-hand sides

33
Q

What is a drag force?

A

a force that acts in opposition to motion

34
Q

What are the 2 types of drag force?

A
  • surface drag= friction between the surface of an object and the fluid environment
  • form drag= the impact of the fluid environment on an object e.g. streamlining
35
Q

What is streamlining?

A

involves shaping the body so it can move as effectively and quickly through a fluid as possible

36
Q

What is lift force?

A

Causes a body to move perpendicular to the direction of travel

37
Q

What is the Bernoulli principle?

A

where air molecules exert less pressure the faster they travel and more pressure when they travel slower

38
Q

What is the angle of attack?

A

the tilt of a projectile relative to air flow

39
Q

Give an example where a sport limits surface drag

A

swimmers wear smooth clothing to reduce friction between them and the water

40
Q

Give an example where a sport reduces form drag

A

cyclists have streamlined bikes where the handlebars don’t stick out and they occupy a crouched position so air travels over them. swimmers also create a streamlined position as they go through the water

41
Q

State the factors that reduce and increase drag

A
  1. velocity of the moving body- the greater the velocity, the more drag force created, streamlining can reduce this
  2. cross-sectional area of the moving body- a large area increases drag
  3. shape and surface characteristics of the moving body- streamline and aerodynamic shape reduces drag
42
Q

Give an example where reversed Bernoulli’s principle would occur

A

cyclists maintain a low streamlined position over the handlebars which means the air that travels over the top has to travel a shorter distance than the air underneath so the air above travels at a slower velocity which creates high pressure so a downward lift force is created

43
Q

What is 1 radian in degrees?

A

1 radian=57.3 degrees

44
Q

What 2 forces affect the flight path of projectiles?

A
  • weight(gravity)

- air resistance

45
Q

What flight path does a shuttle cock follow and why?

A
  • distorted parabola
  • lighter mass so air resistance has a greater affect
  • unusual shape increases air resistance
46
Q

What are the vector components of parabolic flight?

A

horizontal component= the horizontal motion of an object

vertical component= the upward motion of an object

47
Q

What 3 factors affect friction?

A
  • the surface characteristics of the 2 bodies in contact e.g. spikes help to increase friction in a runner
  • the temperature of the 2 surfaces in contact
  • the mass of the objects sliding
48
Q

What are the 2 types of force acting on a performer during linear motion?

A
  • internal

- external

49
Q

What is an internal force?

A

applied/generated when our skeletal muscles contract

50
Q

What is an external force?

A

comes from outside the body e.g. weight, air resistance, gravity, friction

51
Q

What are the 2 types of external force?

A

vertical and horizontal

52
Q

Which external forces are vertical?

A

-gravity, weight and reaction force

53
Q

Which external forces are horizontal?

A

air resistance, friction

54
Q

What are the 2 types of friction force?

A
  • static

- sliding

55
Q

What is static friction force?

A

static friction force is the force exerted on one surface by another when there is no motion between the 2 surfaces (static friction occurs before an object starts to slide)

56
Q

What is sliding friction force?

A

sliding friction occurs when there are 2 bodies in contact with one another that have a tendency to slip/slide over each other

57
Q

What factors affect air resistance?

A
  • velocity of the moving body: faster the performer moves, the greater the air resistance
  • cross-sectional area of the moving body: larger the cross sectional area, greater the air resistance
  • shape and surface characteristics of a moving body: streamlined shape and smooth clothing reduce air resistance
58
Q

How is a weight arrow drawn in a free body diagram?

A

always drawn down from the centre of pass

59
Q

How is an air resistance arrow drawn in a free body diagram?

A

drawn from the centre of mass, opposing the direction of motion of the body

60
Q

How is a friction arrow drawn in a free body diagram?

A

starts from where the 2 bodies are in contact with each other and is in the opposite direction to any potential slipping e.g. a runner may slip backwards so the friction arrow is drawn forwards

61
Q

What is impulse measured in?

A

newton seconds. it is the time it takes a force to be applied to an object or body

62
Q

How do you use impulse to increase momentum?

A

increase the amount of:

  • muscular force applied
  • time in which a force is applied
63
Q

How do you use impulse to decrease momentum?

A

increase the time forces act upon the body or object e.g. 60m indoor sprint, athletes push their feet hard into the ground to increase the contact time of the foot with the ground so they can decelerate quickly