Unit 3 - AOS 1 - Biomech

Question 1

Biomechanics

Answer 1

Study of mechanical principles that govern human movement. Can govern and enhance sporting techniques aiming to optimise the technique

Question 2

Kinetics

Answer 2

Is the study of forces that cause motion

Question 3

Kinematics

Answer 3

Is the description of motion

Question 4

Linear motion

Answer 4

Straight line / curved path

Question 5

Angular motion and cause (eccentric …)

Answer 5

Angular motion is motion around an axis in which the body/object moves in a circular path at the same angle, in the same direction, and at the same time.

• Caused by an eccentric force - Torque

Question 6

Torque

Answer 6

Torque = force x lever arm
- Is the tendency for an object to rotate
- greater torque = greater acceleration of rotation

Question 7

Lever arm ( in relation to torque)

Answer 7

Is the distance between where the force was applied and the centre of gravity/ point of axis.

Question 8

Moment of inertia

Answer 8

Moment of inertia = mass x radius (squared)
- describes the reluctance of a body to change its state of motion either at rest or reluctance to change direction or velocity when in motion

Question 9

Linear momentum

Answer 9

Linear momentum = mass x velocity
- Is a measure of the amount of motion a body of mass has and it’s resistance to changing that motion

• always stays the same!! (Conserved )’

Question 10

Example of linear momentum

Answer 10

The higher the mass and velocity, the higher the momentum.
- big brother and little brother yoga ball fail

Question 11

Conservation of momentum

Answer 11

the total amount of momentum before 2 bodies collide is equal to the amount of momentum afterwards.

e.g. 2 footy players crashing (force continues downwards)

Question 12

Moment of inertia (mass and radius) distribution, in relation to make angular motion have a higher angular velocity?

Answer 12

Mass close to axis of rotation = easier to rotate
(e.g. somersault)

Radius is shorter resulting in mass being closer to axis of rotation (e.g. bending knee when running)

Question 13

Newtons first Law

Answer 13

The law of inertia: An object will remain at rest or continue to travel in the same direction at a constant velocity unless acted upon by an unbalanced, external force

• The higher the mass of a body the greater the inertia and therefore more force is required to overcome this inertia.

Question 14

Newtons Second Law

Answer 14

The Law of acceleration: The rate of acceleration of a body is proportional to the force applied to it and in the direction in which the force is applied

Question 15

If force is the same higher and lower mass will result in ?

Answer 15

Higher mass = lower acceleration
Lower mass = higher acceleration

Question 16

Newtons Third Law

Answer 16

For every action there is an equal and opposite reaction

Equal = amount of force
Opposite = Direction

• When one object applies force to a second object, the second object applies equal force to the first object.

Question 17

Force

Answer 17

mass x acceleration
Friction - opposes the movement of an object ( is a factor )

Question 18

Impulse

Answer 18

Is the amount of force required to change the momentum of an object
impulse = force x time

• the greater the impulse the greater the change in momentum

Question 19

Examples of impulse

Answer 19

E.g push pass in hockey - longer contact time with the ball (=more momentum)

E.g strike in hockey- shorter time but higher force is applied (=higher change in momentum than push pass)

Question 20

High and low peak force (impulse)

Answer 20

Impulse can be used to absorb the force over a longer period of time to reduce force of impact.

( Impulse is the same but time and force is manipulated)
E.g Landing without and with bent knees
high peak force - higher force over a shorter period of time
Low peak force - same momentum but force is applied over a longer period of time ( reduces risk of injury )

Question 21

Summation of force/momentum definition

Answer 21

Body parts move in sequence to produce the desired degree of force ( timing)

Question 22

Factors involved in summation of force/momentum

Answer 22

• strongest and largest muscle groups activated first
• use as many body parts as possible, to enable force to be generated over a greater length of time
• transfer momentum from one body part to another when at maximum velocity
• stable base of support
• follow through to prevent deceleration

Question 23

Linear distance

Answer 23

Is the overall path travelled by an object

Question 24

Displacement

Answer 24

Difference between starting point and ending point

Question 25

Speed

Answer 25

• Average time taken to complete the event
• speed = distance / time

Question 26

Velocity

Answer 26

Different points of speed during the event, taking acceleration and deceleration into consideration

Velocity = displacement / time

Question 27

Projectile motion

Answer 27

When an object is air born. Once in the air the object is under influence from air resistance ( horizontal) and gravity (vertical )

Question 28

Factors of release during projectile motion

Answer 28

Angle of Release
- optimal is 45 degrees

Speed of Release
- greater speed = greater distance
(N 2nd law)

Height of release
- ( if speed and angle are constant) —> throw released from higher point will travel further

Question 29

Equilibrium

Answer 29

a state in which there is a balance in forces or influences in opposition to each other.

Question 30

Angular momentum !!!!

Answer 30

Moment of inertia x angular velocity