Component 1 - existing exam questions for topics so far Flashcards
Define Newtons first law
A body remains at rest or constant velocity until acted upon by an external force
Apply Newtons first law to a performer kicking a ball
the ball remains at rest until the force of the kick is applied to it
Define Newtons second law
- A body’s rate of change of acceleration is
proportional to the size of the force applied - acts in the direction
in which the force acts - force = mass x acceleration
Apply Newtons second law to a performer kicking a ball
- the bigger the force of the kick, the faster the ball will accelerate
- e.g. the ball will accelerate/ start to move in the direction of the force of the kick
- the rate of change of acceleration of the ball is proportional to the size of the
force from the kick/foot of the performer
Define Newtons 3rd Law
For every force applied to a body there is an equal and opposite reaction force
Apply Newtons 3rd Law to a performer kicking a ball
when the foot applies a force to the ball, the ball applies a force that is equal and opposite onto the foot
Identify 4 factors affecting air resistance
- Velocity
- Shape
- Frontal cross - sectional area
- Surface characteristics
Explain the effects of the vertical forces on the motion of the performer during the
execution phase of the vertical jump
- The reaction forces are greater than the weight force
-There is a resultant force acting upwards - Acceleration occurs upwards
- Performer jumps upwards
- If the net upwards force is large enough to overcome the mass of the performer
- The larger the net force upwards, the greater the acceleration upwards.
Describe the use of limb kinematics to analyse movement in sport
- Reflective markers placed on bony landmarks of the performer
- Performance of the technique is recorded using multiple infra-red cameras
- Information is downloaded to computer
- Gives a record of the motion in digital format
- Used to assess movement efficiency
Centre of mass definition
Centre of mass is the point at which a body is balanced in all directions
What does position of centre of mass depend on
distribution of mass in the body
how is centre of mass and weight related
it is the point where weight acts from
When a sprinter is crouched at the start of the raise, what happens to com
- it lowers to the ground
- it moves forwards
= manipulated by changing body shape
Stability
the ability of a body to resist motion
what affects stability
- mass
- height of centre of mass
- line of gravity
- base of support
If a sprinter has an increased muscle mass, what will happen
- more stable
- more force is required to overcome athletes inertia
how does height of com affect the sprinter
- at sprint start athlete is more stable as they are in a low crouch
- when they raise their hips, com raises, so they are less stable
- when they begin to run, com raises more, even less stable
why does the athlete need to create instability
- to leave the blocks
line of gravity
imaginary line that extends vertically downwards from com
how does line of gravity affect a sprinter
- start crouch, it falls to the centre of bos, so more stable
- when athlete moves shoulders in front of hands, log moves towards edge of bos = less stable
Hip - joint type
ball and socket
ball and socket
3 planes of motion
when in sprint start position, what joint movement are sprinters hips in
flexion
when sprinter drives up to start running what joint movement is happening at the hip
extension
plane of flexion / extension
sagittal
flexion at hip - muscle
illiopsoas
extension at hip - muscle
gluteus maximus
what happens to muscles in hip flexion
- illiopsoas contracts = agonist
- gluteus maximus relaxes = antagonist
- hamstring group ext and quadricep group flex = also contribute to hip action
- mention concentric contraction here
when sprinter starts moving - muscle action - extension at hip
- gluteus maximus = agonist - contracts
- illiopsoas = antagonist - relaxes
isometric contraction
involves tension in muscle but no movement
sprinter - isometric contraction - sprint start
- at hips
- maintains balance
concentric contraction
muscle shortens under tension to cause movement
more powerful the contraction ..
faster sprint start
explain how conduction system of the heart controls diastole
- atria relax = atria/ventricles do not contract
- due to no electrical impulse
Describe how the use of a wind tunnel could help an elite track cyclist to enhance their performance
- collects data on cyclist / bike/ equipment
- optimises aerodynamics around bike
-optimises streamline around cyclists clothes - optimise aerodynamics around body position
agonist muscles during flexion at the knee
- Biceps Femoris
- semi-membranosus
- semi-tendinosus
plane of motion - flexion
sagittal
Explain how neural factors control heart rate at the start of exercise and during recovery
- Heart rate regulated/controlled by the autonomic nervous system/ANS
- Cardiac control centre receives information from the
receptors - Chemoreceptors detect increased
(pp)CO2/acidity/lactic acid or decreased (pp)O2/pH - proprioceptors detect (increased) motor activity/movement
- baroreceptors detect increased blood pressure
- SA node increases firing rate/HR
RECOVERY - (Receptors) Chemoreceptors detect decreased (pp)CO2/acidity/lactic acid or increased (pp)O2/pH
- proprioceptors detect decreased motor activity/movement
- baroreceptors detect decreased blood pressure
- parasympathetic nervous system (to decrease HR)
- Vagus nerve (stimulated)
- SA node decreases firing rate/HR
how long does acclimatisation take at high altitudes
- 2 weeks minimum
describe physiological processes of acclimatisation to altitude
- Increased release EPO
- Increased red blood cell
- increased capillarisation
- Breathing rate/ventilation stabilise
- Decrease in stroke volume/cardiac output/Q
- Decrease in altitude sickness/headaches/poor sleep/lack of
appetite
Name sports where anabolic steroids may be used
- rugby
- weightlifting
- sprinting
positives - anabolic steroids
- increased muscle mass
-Increased maximal/explosive strength/power - Increased speed of recovery
- Increased intensity/duration/quality/quantity of
anaerobic/(near) maximal training
negatives - anabolic steroids
- hormone imbalance
- Liver/kidney/heart disease/damage
- Increased blood pressure
- Increased aggression/irritability/low mood
why is shoulder flexibility important for a swimmer
- swimmer can apply force over an increased distance/time
- swimmer moves a greater distance through the water
- swimmer is more efficient
- same distance/achieves faster times/swims quicker
- decreased risk of injury
why do performers want to increase friction
- allows greater acceleration/deceleration/change of
direction/speed/velocity/drive force - to improve grip/decrease the chance of their foot/feet slipping/increase stability
how do performers increase friction
- Increased roughness of footwear/tyres e.g, athletes wear spikes gymnasts
chalking/taping hands - Increased softness of contact surface, e.g rubber soles on training shoes
- Increased roughness of ground surface, e.g cross country runner choosing to run a line on rougher ground/rubber/tartan track
- Increased temperature, e.g heating tyres /warm up laps in motor sports
A basketballer jumps upwards from 1 foot to reach a rebound
Explain the resulting motion of the basketballer
- Reaction force is greater than weight
- net force upwards
-There is acceleration upwards
-The basketball player leaves the ground
