Biomechanic principles

Question 1

motion

Answer 1

the change in position of a body in relation to time

Question 2

linear motion

Answer 2

Occurs either in a straight line or curved path (or a combination of these in the case of general motion)

Question 3

rectilinear motion

Answer 3

-Movement in a straight line
-where all parts of a body travel the same distance, in the same direction, at the same time (e.g. a young child sledding down a mountain on a toboggan).

Question 4

curvilinear motion

Answer 4

• Movement over a curved path
  -e.g. the path of a ball thrown through the air until gravity forces it to the ground).

Question 5

angular motion

Answer 5

• takes place when a body moves along a circular path
  -body moves along a circular path at the same angle, in the same direction, at the same time. Angular motion occurs around some type of axis,

Question 6

general motion

Answer 6

the combination of linear and angular motion

Question 7

mass

Answer 7

the quantity of matter found within a particular body

Question 8

inertia

Answer 8

the resistance of a body to a change in its state of motion

Question 9

force

Answer 9

the product of mass and acceleration

Question 10

distance

Answer 10

the length of space between two points

Question 11

displacement

Answer 11

the difference between the initial position and final position of an object

Question 12

force summation

Answer 12

the correct timing and sequencing of body parts to produce maximal force

Question 13

torque

Answer 13

a force that is applied at a distance away from the centre of mass, that causes the object to rotate

Question 14

moment of inertia

Answer 14

of inertia a measure of an object’s resistance to change in its rate of rotation

Question 15

Newton’s First Law of Motion
(law of inertia)

Answer 15

object will stay at rest or continue to travel in the same direction at a constant velocity unless acted on by an unbalanced force

Question 16

Newton’s Second Law of Motion

Answer 16

states that 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 17

Newton’s Third Law of Motion

Answer 17

states that for every action, there is an equal and opposite reaction

Question 18

first-class lever

Answer 18

axis in the middle, between the force and the resistance.

Question 19

second-class lever

Answer 19

always has the resistance in the middle.

Question 20

third-class lever

Answer 20

will always have the force in the middle.
-most common
-built to amplify speed

Question 21

projectile

Answer 21

projectile is any airborne object

Question 22

main factors of projectile motion that athletes can control and manipulate are the…

Answer 22

speed of release

angle of release

height of release.

Question 23

Speed of release

Answer 23

Larger force applied will result in a further distance

Question 24

Desirable angle of release

Answer 24

45 degrees

Question 25

How does angle of release effect a projectile?

Answer 25

The angle of release determines the effects of gravity and air resistance on the projectile

Question 26

Equilibrium

Answer 26

All forces are balanced

Question 27

Static equilibrium

Answer 27

is the state in which a body has zero velocity and zero acceleration. A body is in equilibrium when the sum of all forces and the sum of all movements acting on the body are zero

Question 28

Dynamic equilibrium

Answer 28

the state in which a body is in motion with a constant velocity

Question 29

Stability

Answer 29

degree to which a body resists changing its equilibrium

Question 30

Balance

Answer 30

ability of the body to remain in a state of equilibrium while performing a desired task

Question 31

Increasing stability and balance

Answer 31

Lower the centre of gravity. Ensure the line of gravity is over the base of support. Increase the size of the base of support.

Question 32

Reducing stability and balance

Answer 32

Raise the centre of gravity Shift the line of gravity to the edge or outside the base of support. Narrow the base of support.

Question 33

4 stages of qualitative analysis include ...

Answer 33

-Preparation -Observation -Evaluation -Error correction