1.3a Physiology

Question 1

define linear motion

Answer 1

motion in a straight line or curved line, with all body parts moving the same distance, speed and time

Question 2

what is newtons first law of motion

Answer 2

• Inertia - a body will continue in its state of rest or motion in a straight line, unless external forced are exerted upon it

The greater the mass the greater the inertia to change its state

• examples: sprinter in blocks will stay there, the greater the performers mass the greater the inertia needed to get out of the blocks
• suddenly stop in a car and feel body thrown forward, ahppens as body wants to continue at the same speed of the car

Question 3

what is newtons second law of motion

Answer 3

• Acceleration - the rate of change of momentum of a body is proportional to the force causing it and the change that takes place in the direction in which the force acts

**examples: **
* greater the force applied to the sprinter at the start the greener the momentum and therefore the acceleration away

Question 4

how to calculate force

Answer 4

force = mass x acceleration

therefore as mass increases the greater amount of force required to get the same acceleration

Question 5

what is newtons third law of motion

Answer 5

• Reaction - to every action there is an equal and opposite reaction

example:
* during start if the performer applies a downward force to the starting blocks, the blcoks will provide and equal and opposite force back thus propelling the athlete forward
* ball hits of the goal posts so go backwards towards you

Question 6

name all the measurments of biomechanics

Answer 6

• force
• interia
• speed
• acceleration
• displacement
• momentum
• mass
• distance
• weight
• decelartion
• velocity

Question 7

what are the 2 types of force

Answer 7

• internal - generated through the contraction of skeletal muscle
• external - forces come from outside the body

Question 8

what 3 factors will effect generated force

Answer 8

• direction of force - of a corce is apllied through the middle of the object it will move in the same direction as the force
• size of force - dependant on size and number of muscle fibres used
• application of force - applying force straight through the centre results in movements in a straight line (linear motion) whereas off centre reuslts in spin (angular momentum)

Question 9

define net force

Answer 9

the resultant force acting on a body when all other forces have been considered

Question 10

define balanced forces

Answer 10

when there are two or more forces acting on the body that are equal in size but opposite in direction

Question 11

define unbalanced force

Answer 11

when a force acting in one direction on a body is larger than the force acting in the opposite direction

Question 12

what are the 2 vertical forces

Answer 12

1. weight - gravatational force that pulls the body down
2. reaction - means that there is always a reaction force whenever two bodies are in contact with one another

Question 13

what are the 2 horizontal forces

Answer 13

1. friction - occurs whenever there are two bodies in contact with eachother
2. air resistance - opposes the motion of a body travelling

Question 14

define speed and its calculation

Answer 14

• the rate of chnage of position
• speed = distance / time

scalar quantity becuase it doesnt consider direction

Question 15

define velocity and its calculation

Answer 15

• the rate of change of position with reference to direction
• velocity = displacement / time

vecotr quantity

Question 16

acceleration calculation

Answer 16

final velocity - initial velocity / time

Question 17

define momentum and its calculation

Answer 17

• the product of mass and velocity of an object
• momentum = mass x velocity

Question 18

define centre of mass

Answer 18

at the point which the body is balanced in all directions

its location is around the naval when satnding straight

Question 19

define stability

Answer 19

the ability to resist motion applied to it, alos the ability to withstand a force and return back to the original position

Question 20

factors affecting stability (centre of mass)

Answer 20

• mass of the body - greater the mass greater the ineria required
• height of the centre of mass - lower centre of mass greater the stability
• base of support - greater size of base greater the stability
• line of gravity - more central the line the more stability

Question 21

what are the 3 lever systems

123 FLE

Answer 21

• First class
• second class
• thrid class

Question 22

what are the 2 functions of levers

Answer 22

1. increase speed in which the body can move - longer the lever distance from the force to the fulcrum the greater the speed generated
2. to increase the resistance that a given effort can move - the closer effort is to the fulcrum, the greater the distance moved

Question 23

what are the 3 components of a lever

Answer 23

• Fulcrum (F)- the fixed point of pivot
• Effort (E) - point where force/effort is applied
• Load (L) - point where weight/resistance is coming from

Question 24

what is a first class lever and examples

Answer 24

• first class lever has the fulcrum in the middle, the effort and load either side
• first class levers can increase both effects of effort and the speed of a body

For example: heading the ball in football

Question 25

what is a second class lever and examples

Answer 25

* second class lever has the load in the middle, effort and fulcrum either side * tend to increase the effort of the effort force | For example: jumping to dunk in basketball

Question 26

what is a thrid class lever and examples

Answer 26

* third class lever has the effort in the middle, with load and fulcrum either side * very ineffective lever but allows speed and range of movement (used to increase the speed of body) | For example: a bicep curl

Question 27

what is the resistance arm

Answer 27

* part of the lever between the fulcrum and the load * the longer the reisstance arm the greater the speed generated

Question 28

what is the effort arm

Answer 28

* the distance between the fulcrum and the effort * the longer the effort arm the less effort rquired to move * sports using rackets increase the length of the effort arm which will increase the force that an object is struck

Question 29

what is mechanical advanatge and which lever is the best for mechnical advantage

Answer 29

* a mechanical advnatge is where the reisstance arm is greater than the effort arm, this means you can move a larger load with less effort * second class levers have the highest mechanical advantage as they can move large loads with relatively small effort

Question 30

define limb kinematics and describe what it is

Answer 30

* **the study of movement in relation to time and space** * this is the study of movement using motion analysis technology. * Infra-red cameras link up to a computer to rpovide movement and can be played back and slowed down to provide vital feedback on limb position

Question 31

what are the pros and cons of limb kineatics

Answer 31

**Pros**: * helps improve technique therefore performance * helps prevents injury **Cons**: * expensive equipment * experience needed * poor inter-reliability of boyd mark placement

Question 32

define force plates and describe what it is

Answer 32

* **ground reaction forces are measured in laboratory conditions using force plates ** * athletes balance, run and jump on force plates which assesses their power otuput. Data on running, jumping and balacning can be recorded, most common use is for gait analysis (running), balance and rehabilitation

Question 33

what are the pros and cons of force plates

Answer 33

**Pros**: * helps analyse gait which is important for the efficiency of movement * helps to measure force produced - can know which legs produces more power during a jump * help improve balance **Cons**: * specialist equipment needed * expensive equipment * specialist knowledge required on how to use them and what they are looking at

Question 34

define wind tunnels and what it is

Answer 34

* **steel frame buildings which contain wide fans, where artifical wind is produced ** * technology used to develop drag reduction system * the aerodynamics of a cycle helmet or an F1 racing car can be the small amrgins needed to win. Engineers will sutdy the flow of air around the object to test aerodynamic efficiency. * The ability to control varibales gives the performer and coach an understanding of what will perform the best in different environments

Question 35

what are the pros and cons of wind tunnels

Answer 35

**Pros**: * helps with streamlining thus increasing lift * decreasing drag **Cons**: * specialist equipment needed * equipment is expensive