PE section A

• the three energy systems


  aerobic system

  the ATP-PC system

  the aerobic glycolitic system
• first stages of the aerobic system


  Glycolysis - takes place in the sarcoplasm of the muscle cell, is the breakdown to pyruvic acid. for every molecule of glucose undergoing glycolysis 2 atp are formed
• second stage of aerobic system

  krebs cylce - occurs in the matrix of the mitochondria

  acetyl groups combine with oxaloacetic acid forming citric acid

  oxidative carboxylation - oxygen and carbon given off

  carbon forms carbon dioxide transported to lungs and breathed out

  produces 2 atp molecules
• third stage of aerobic respiration


  electron transport chain - hydrogen carried to electron transport chain by hydrogen carriers

  occurs in the cristae of the mitochondria

  hydrogen splits into hydrogen ions and electrons then charged with potential energy

  produces 34 ATP
• the ATP-PC system


  uses phosphocreatine as its fuel (PC)

  rapid availability for single maximal movement such as the long jump

  duration: 5-8 seconds

  only be replenished during low intensity when oxygen is available
• Aerobic glycolytic system


  produces high powered energy for high intensity effort eg 400m

  duration depends on the fitness of the athlete

  resynthesises atp from the breakdown of fuel glucose supplied from digestion of carbohydrates

  stored in the liver as glycogen
• energy continuum


  describes the type of respiration used by physical activities
• EPOC


  the amount of oxygen consumed during recovery above that which would have been consumed at rest during the same time.

  there are two main components of EPOC:

  the fast components - restoration of atp and phosphocreatine and restoration of myoglobin

  the slow component - removes lactic acid (cori cycle), maintenance of breathing and heart rate, glycogen replenishment, increase in body temperature
• newtons first law of motion


  an object will continue in a state of constant velocity until compelled to change by an external force
• newtons second law of motion


  an object will accelerate proportional to the force acting and in the direction of that force
• newtons third law of motion


  for every action there is an equal and opposite reaction
• centre of mass


  point in the body where mass is distributed evenly in all directions

  roughly at the naval/belly button
• factors affecting centre of mass

  distribution of mass

  movement of limbs

  uniformity of shape
• stability

  the higher the centre of mass the less stable the body becomes

  the greater the mass the more stable

  base of support - broader the base the more stable

  line of gravity above the base
• first class lever

  123

  FLE

  
• second class lever

  123

  FLE

  
• third class lever

  123

  FLE

  
• two main roles of levers


  1.overcome large loads with little effort

  2.produce wide range of movement or fast movement
• mechanical advantage

  over come large loads with little effort possible

  long effort arm - distance from fulcrum to effort

  2nd class lever have high mechanical advantage
• mechanical disadvantage


  range of movement and speed

  long resistance arm

  all 3rd class lever has high mechanical disadvantage

  some 1st class levers have mechanical disadvantage
• vector quantity

  both direction and magnitude

  • displacement
  • velocity
  • force
  • weight
  • momentum
  • angular displacement
  • angular velocity
• scalar quantities


  magnitude only

  • distance
  • speed
  • mass
  • angular distance
  • angular speed
• drawing pin/vector diagrams


  rules:

  • correct vector origin
  • correct vector direction
  • correct vector magnitude (length)
• impulse


  impulse is relevant when two objects collide:

  • impact
  • size of acting force
  • time that the force is applied for

  a greater impulse means a greater change in momentum
• impulse equation

  impulse = force x time
• newtons first analogue

  a rotating body will continue in a state of constant angular momentum until an external torque acts upon it
• newtons second analogue 


  angular acceleration is proportional to the torque acting and takes place in the direction of that torque
• newtons third analogue

  an object will always apply a reaction torque in proportionate size but opposite in direction
• angular momentum


  a rotating body will continue in a state of constant angular momentum until an external torque acts upon it
• the law of conservation of angular momentum


  angular momentum = angular velocity x moment of inertia
• graph of angular momentum

  conservation of angular momentum

  
• factors affecting projectiles

  .

  1. velocity of release - horizontal distance
  2. increased velocity = increased distance
  3. height of release
  4. angle of release
• non-parabolic flight path

  occurs when weight is dominant

  eg shuttlecock

  asymmetrical flight path
• resultant forces


  3 types of resultant forces:

  1. zero net force
  2. upwards force
  3. downwards force