PE EXAM STUDY Flashcards
Newton First law of motion (Inertia)
Inertia is a body’s resistance to change its motion.
- A heavy body is harder to move or slow down because it has a greater mass.
- Inertia is directly related to mass.
- An object at rest will remain at rest unless acted on by an external force.
- An object in motion will continue in motion unless acted on by an external force. E.G., Ball travels less distance in the wind.
Newtons Second law of motion (Force)
The acceleration of an object is directly proportionate to the amount of force applied and inversely proportionate to its mass.
Acceleration = Force/mass
Force = Mass x Acceleration
Newtons Third law of motion (action and reaction)
For every action there is an equal and opposite reaction
- Action force (push on ground) reaction force (take off from ground)
Angular Motion
Angular velocity
Angular velocity is referred to as the speed of rotation or in other words, how quickly something rotates
Moment of inertia
he moment of inertia is referred to as the resistance of a body to change state when rotating. Its reluctance to rotate. If a body has a high reluctance to rotate, it will have a lower angular velocity. If a mass has a low resistance to rotate, then it will have a higher angular velocity.
Moment of inertia = mass x distance from the axis of rotation
Momentum
A measure of motion, Momentum = Mass x Velocity
- A heavy fast-moving body has large momentum
- A lights slow-moving body has low momentum
- A stationary body has no momentum but has inertia
Levers
The smaller the lever the more control you have over the lever and the direction the ball is going. When you lengthen a lever, you will aloe someone to apply more force.
First class levers
used to generate great speed. Axis is between the force and resistance. (FAR)
- Examples, rowing oar, crowbar, scissors
Second class levers
Used to increase the strength that humans can apply to objects. Resistance is between the axis and the force (ARF). Force arm is always longer than the resistance.
- examples, wheelbarrow and bottle opener.
Third class levers
The most common in the body. The force is between the axis and resistance (AFR).
- Examples, Bicep curl, Kicking a ball
Factors affecting the flight or projectiles.
speed of release, most important the greater the velocity at release = greater distance.
- Angle of release
- Height of release, as Hight of release increases so does distance.
- Gravity
- Air resistance
Angle of release
when throwing for distance, the optimal angle of release is 45 degrees which provides equal components of vertical and horizontal force.
- However, as spin and air resistance are usually present the optimal angle of release is between 35 and 45 degrees
- the optimal angle of release depends on, Hight of realise, velocity of release, shape, and mass of projectile.
Air Resistance
Air resistance markedly reduces the distance of throw or hit. Eg in a vacuum a soccer ball kicked at 35m/s at an average of 45 degrees would travel 125 meters in reality it travels only 65 meters due to air resistance.
- The air acts in two ways as the projectile travels through it. First as a frictional force through which the projectiles has to push and second as the air is disturbed it creates a drag force.
- the effect of air resistance depends on size, shape, mass, momentum and velocity of projectile and spin.
Types of movement skills
Open- are performed in a constantly changing and externally paced environment eg, the changing of speed, Hight, force, and direction. (a sport in which the speed of a ball variers).
Closed- are performed in a predictable, self-paced environment where there are no interruptions or changes in the surroundings. Eg, gymnastic moves, indoor archery.
Fine- involves the cooperative use of small muscle groups and the senses of sight and touch eg writing by hand
Gross- involves a combination of large muscle actions that result in a coordination movement eg, skipping.
Discrete- involve movements of brief duration, and they are easily defined by a distinct beginning and end. Eg a kick, throw, or catch.
Serial- are a series or group of discrete skills strung together to create a more complicated. Eg performing a gymnastic routine.
Continuous- have no distinct beginning or end eg, swimming.
Task constraints
ask-related constraints include the rules of the game, equipment used, and the speed and accuracy required.
- level of pressure
- rules, eg 3 secs, contact, off-side.
- area/size
- number of players
- time
- scoring method
- zones/areas
- equipment, modified, size, weight
Environmental constraints
- Environmental constraints are those that are external to the individual such as the weather, sociocultural restraints, and gravity.
- Court surface
- temperature, weather
- background noise
- motivation of peers
- crowd, spectators
- peers, teachers watching
- cultural factors
Coaching approaches – direct
The direct approach is an instructor-oriented approach to coaching movement skills; learner is told what to do and how to do it.- Skill and Drill
- Explicit instruction
- Necessary for beginners
Coaching Approaches – constraints based.
The constraints-based approach to instruction encourages the learner to discover effective skill technique- Promotes decision making
- less likely to choke in the pressure of the real game.
- can be more fun and engaging for learners
Practice Distribution
Massed practice- continuous repetition of a skill
Little or no rest
Often used for discrete, closed skills to ingrain a correct technique.
Advantages of constraints-based coaching.
The constraints-based approach has a number of advantages.
- Practice closely replicates the game environment, facilitating the development of more applicable skills.
- Practice is more varied ensuring the development of versatile skills, as well as providing the learner with a more interesting and engaging learning environment.
- the learning is implicit
- implicit learners make better problem solvers and are less likely to choke at times of stress.
- it develops both technical and tactile awareness.
- it engender independent/autonomous learning
Respiratory System
Ventilation- the amount of air we inhale per minute.
Tidal Volume- the amount of air inhale per breath
Respiratory rate- the number of breaths we take per minute.
V = TV x RR
