3.1 Biomechanics

Question 1

What is netowns first law of motion?

Answer 1

Inertia – states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. It is the reluctance of a body to change its state of motion

Question 2

What is newtons second law of motion?

Answer 2

• Acceleration of a body is proportional to the force causing it and the acceleration takes place in the direction in which the force acts
• F=ma

Question 3

What is scaler motion?

Answer 3

no direction but movement

Question 4

What is vector motion?

Answer 4

direction and movement

Question 5

What is newtons third law of motion?

Answer 5

• When one object exerts a force on a second object, there is an equal and opposite force exerted by the second object on the first
• For every action there is an equal and opposite action

Question 6

What are all the vertical forces?

Answer 6

• gravity

- reaction force

Question 7

What is reaction force?

Answer 7

where the points of contact are

Question 8

Where is gravity acting from?

Answer 8

center of mass

Question 9

What are the horizontal forces

Answer 9

air resistance

friction

Question 10

WHere does friction act from

Answer 10

point of contact

Question 11

Where does air resistance acto from?

Answer 11

center of mass to behind you

Question 12

What is linear motion?

Answer 12

straight line

Question 13

What is angular motion?

Answer 13

rotation about a particular point (axis of rotation)

Question 14

What is general motion?

Answer 14

rotation and straight line motion

Question 15

What is velocity?

Answer 15

rate of change in displacement

Question 16

WHat is the velocity equation?

Answer 16

displacement / time taken

Question 17

What is momentum?

Answer 17

quantity of motion possessed by a moving body

Question 18

What is momentum equation?

Answer 18

mass x velocity

Question 19

What is acceleration?

Answer 19

rate of change in velocity a

Question 20

acceleration equation?

Answer 20

(final velocity - initial velocity) / time taken

Question 21

What is force

Answer 21

push or pull that alters the state of motion of a body

Question 22

How do you calculate force?

Answer 22

mass x acceleration

Question 23

What is net force (resultant force) ?

Answer 23

the sum of all forces acting on the body

Question 24

What is reaction?

Answer 24

the equal and opposite force exerted by a body in responce to the action force placed upon it

Question 25

Force causes a moving body to?

Answer 25

- change direction - Accelerate - Decelerate

Question 26

What is the centre or mass?

Answer 26

the point at which the body is balanced in all directions, or where all the mass could be considered to be concentrated

Question 27

What is the center or mass continuously doing?

Answer 27

changing

Question 28

What is stability?

Answer 28

the ability of a body to resist motion and remain at rest

Question 29

What are the factors effecting stability?

Answer 29

- mass of the body - height of the center or mass - base of support - line of gravity

Question 30

How is the fosbury flop beneficial?

Answer 30

- uses j curve to allow greater velocity - plants outside leg to allow inside leg to lift, along with arms, at take off to raise the center of mass as high as possible - fully extends spine to rotate around the bar moving the center of mass outside of the body and below the bar. Only one section of body has to be above the bar at one time. ( center of mass passes underneath the bar, fosbury flop requires less take off force to clear the same height as earlier techniques . when maximum force is generated at take-off greater heights can be achieved.)

Question 31

How does mass effect stability?

Answer 31

greater mass, greater inertia , greater stability

Question 32

How does height of center or mass effect stability?

Answer 32

lower center of mass, greater stability

Question 33

How does base of support effect stability?

Answer 33

greater size of the base, greater stability

Question 34

How does the line of gravity effect stability?

Answer 34

more central line of gravity to the base of support, greater stability

Question 35

What are lever systems?

Answer 35

co-ordination of our bones and muscles, primarily to create human movement

Question 36

Two main functions of lever systems?

Answer 36

- to generate muscular effort to overcome a given load | - to increase the speed of a given movement

Question 37

What are the 4 component parts of a lever system?

Answer 37

- lever - fulcram - effort - load

Question 38

Give example of a lever?

Answer 38

bone

Question 39

Give example of a fulcram?

Answer 39

joint

Question 40

Explain first class lever?

Answer 40

effort ... fulcrum ..... load

Question 41

Example of first class lever?

Answer 41

extension of neck when preparing to head a football

Question 42

Explain a second class lever?

Answer 42

effort ... load ... fulcrum

Question 43

Examples of second class lever ?

Answer 43

ball of the foot in take off phase of high jump

Question 44

Explian third class lever?

Answer 44

- fulcrum ... effort ... load

Question 45

Example of third class lever?

Answer 45

flexion of elbow during bicep curl

Question 46

What is the distance from the fulcrum to the effort known as ?

Answer 46

effort arm

Question 47

WHat is the distance from the load to the fulcrum known as ?

Answer 47

load arm

Question 48

the greater the distance of the effort or load from the fulcrum ...

Answer 48

more significant the effort or load becomes

Question 49

What is a mechanical advantage?

Answer 49

second class lever systems where the effort arm is greater than the load arm. a large load can be moved with a relatively small effort

Question 50

WHat is a mechanical disadvantage?

Answer 50

third class lever systems where the load arm is greater than the effort arm. a large effort is required to move a relatively small load

Question 51

What does a distance time graph show?

Answer 51

the distance a body travels over a given time

Question 52

What does the gradiant show in a distance time graph?

Answer 52

speed of the body

Question 53

How do you work out distance travelled on a speed/time graph?

Answer 53

area under the graph

Question 54

What is angular motion?

Answer 54

movement of a body or part of a body in a circular path about an axis of rotation

Question 55

What does angular motion result from?

Answer 55

eccentric force being applied to the body

Question 56

What is a torque?

Answer 56

measure of turning force applied to the body

Question 57

Sporting example of angular motion?

Answer 57

gymnastics sommersault

Question 58

What is a principal axis of rotation?

Answer 58

an imaginary line that passes through the center of mass about which the body roatates

Question 59

What are the three axis of rotation?

Answer 59

- longitudinal - transverse - frontal

Question 60

What is the longitudinal axis?

Answer 60

-runs from head to toe through the center of mass

Question 61

What is the transverse axis?

Answer 61

from left to right through the center of mass (somersaults)

Question 62

What is the frontal axis?

Answer 62

runs from back to front through center of mass (cartwheel)

Question 63

What is angular velocity?

Answer 63

rate of change in angular displacement or rate of rotation

Question 64

Equation for angular velocity?

Answer 64

angular displacement / time taken

Question 65

What is moment of inertia?

Answer 65

resistance of a body to change its state of angular motion or rotation.

Question 66

Moment of inertia equation?

Answer 66

sum of (mass x distribution of mass from axis of rotation)

Question 67

Moment of inertia units?

Answer 67

Kgm^2

Question 68

What two factors effect moment of inertia?

Answer 68

mass, distribution of mass from the axis of rotation

Question 69

If moment of inertia is high then what is angular velocity?

Answer 69

low as resistance to rotation is high

Question 70

What is angular velocity measured in?

Answer 70

degrees per second

Question 71

What is angular momentum?

Answer 71

quantity of angular motion possessed by a body

Question 72

equation for angular momentum?

Answer 72

moment of inertia x angular velocity

Question 73

What is angular momentum measured in?

Answer 73

kilogram metres squared degrees per second ( kgm^2deg/s )

Question 74

What is the conservation of angular momentum?

Answer 74

a conserved quantity which remains constant unless an external eccentric force or torque is applied

Question 75

What is the angular analogue of newtons first law of motion?

Answer 75

the angular equivalent of newtons first law of motion, which states: a rotating body will continue to turn about its axis of rotation with constant angular momentum unless acted upon by an eccentric force or torque