Biomechanics

Question 1

Anatomical Position

Answer 1

Position where body is standing straight with the arms at its side and palms facing forward.

Question 2

Body weight

Answer 2

The mass (amount of matter that makes up an object) and acceleration (due to gravity) of an object.

Question 3

Linear motion

Answer 3

Refers to a motion along a line (trajectory or path of an object)

Question 4

Angular motion

Answer 4

refers to the rotation of a whole body or segment (forearm or leg), or an implement (bat, stick or club) about a real or imaginary axis of rotation.

Question 5

General motion

Answer 5

A combination of linear and angular motion.

Question 6

Mass

Answer 6

The amount of matter that makes up an object

Question 7

Inertia

Answer 7

The tendency to do nothing or remain unchanged

Question 8

Momentum

Answer 8

The quantity of motion of a moving body, measured as a product of its mass and velocity

Question 9

Impulse

Answer 9

Something that causes something to happen or happen more quickly

Question 10

Acceleration

Answer 10

How quickly an object is changing its velocity
Calculated using velocity/time
Measured in m/s/s

Question 11

Velocity

Answer 11

A measure of how long it takes you to travel a certain distance
Calculated using distance/time
Measured in m/s

Question 12

Law 1

Answer 12

Inertia

A body will continue in its state of rest or uniform motion in a straight line, unless acted upon by an external force

Question 13

Example of Inertia

Answer 13

A Tee-ball sitting on the tee will remain in that position unless acted upon by an external force (bat or wind). This is the creation of motion
Once hit the ball remain travelling in a straight line unless acted upon by an external force (air resistance, gravity). Air resistance reduces velocity, while gravity pulls the ball down. This is the change of motion

Question 14

Law 2

Answer 14

Law of acceleration

Force is equal to mass ‘times’ acceleration

Question 15

Example of the Law of Acceleration

Answer 15

If we want to change the acceleration of the tee-ball then we have two options (i) change the force applied (ii) change the mass of the ball. Given the mass of the ball is constant, then our only option is to change the force applied at impact
If you want the ball to go further, then you need to apply a greater force; you must swing the bat harder

Question 16

Law 3

Answer 16

Action-reaction

For every force there is an equal but opposite reaction

Question 17

Example of action-reaction

Answer 17

As the bat makes contact with the ball it is the force applied (F2-1) that causes the ball to fly into the air. The ball also applies an equal force back against the bat (F1-2) and this assist in bringing the bat to a stop and also why you feel the ’tingle’ in your hands as the bat vibrates following contact.

Question 18

Rectilinear

Answer 18

Straight line

Question 19

Curvilinear

Answer 19

Curved trajectory

Question 20

Distance

Answer 20

The total distance, measured in metres, that you have travelled from your starting point.

Question 21

Displacement

Answer 21

The change from overall starting position. Measured in metres, the difference between your staring point and finishing point in a straight line.

Question 22

Projectile

Answer 22

A projectile is any object which once dropped or released continues in motion by its own mass and is influenced by downward forces of gravity.

Question 23

Velocity of release

Answer 23

Refers to how fast the object is moving at the time of release
A higher release or take-off velocity will result in an increased horizontal or vertical displacement (depending on angle released)

Question 24

Angle of release

Answer 24

Refers to the angle at which the object is released
The angle of release and velocity of release are directly linked. If you are wanting to jump vertically (HJ) you could approach with an ‘optimal’ velocity NOT with a ‘maximal’ velocity. However if your were wanting to jump horizontally you approach with a ‘maximal’ velocity.

Question 25

Height of release

Answer 25

Refers to the height at which the object is released

to consider height of release we also need to look at the landing or finishing position.

Question 26

Angular distance

Answer 26

How far the body segment or implement rotates from its starting point

Question 27

Angular velocity

Answer 27

How quickly the body segment or implement rotates.

calculation is distance travelled / time taken

Question 28

COG

Answer 28

an imaginary point, which my lie inside or outside the body, about which all of the body’s mass is equally distributed.

Question 29

Base of support

Answer 29

area created by points of contact on the supporting surface

The larger the surface area the greater the balance, however we also need to consider the position of the cog

Question 30

Line of gravity

Answer 30

An imaginary line that extends from the cog to the bos

A more stable position is created when the line of gravity falls within the middle of the bos.

Question 31

Mass - stability

Answer 31

An object with a greater mass would be more difficult to move or change its current motion
A heavier object has more static balance than a lighter object

Question 32

Height of cog

Answer 32

An object with a lower CoG is more stable than a higher CoG

Question 33

Accuracy approach

Answer 33

When the task requires accuracy and the distance is not a problem; like a netball shot or darts throw.
The movement of required body segments occurs at the same time and thus this is referred to as ‘simultaneous summation of forces’
Whilst the final velocity is reduced, the accuracy is vastly improved.

Question 34

Maximum velocity approach

Answer 34

When the task requires a high velocity at release or impact, accuracy is sacrificed to ensure maximal velocities can be achieved; hitting a baseball or teeing off in golf
The movement of required body segments occurs as the previous segment reaches its peak velocities, this is referred to as ‘sequential summation of forces.