Biomechanics 2 Flashcards
Define ‘Momentum’
Momentum is a measure of the amount of motion possessed by a moving body. It is the product of mass and velocity
What is the formula for Momentum
Momentum = Mass x Velocity
An object can only have momentum if?
The object is moving
Define ‘Impulse-Momentum Relationship’
Impulse is the application of force over a period of time to change the momentum of an object.
What is the formula for Impulse
force × time
Impulse in important in what type of situations
impact/collisions
To increase momentum what needs to be done
Increase the force component
To decrease momentum what needs to be done
one typically looks to increase the time component.
What is conservation of linear momentum
Principle states the total momentum of two objects before and after impact are equal.
conservation of linear momentum only occurs because of what
Perfect elastic collisions
What is the ‘Kinematic Chain’
Is a process that determines how to best use body segments depending on the demands of the task
Define ‘Power’ in terms of Summation of Force
More segments used. Forces usually sequentially summated
Define ‘Accuracy’ in terms of Summation of Force
Less segments needed and usually summated simultaneously
What does ‘Simultaneously’ mean in Summation of Force & what is it generally used for
Where all body parts move at the same time to produce a force
- used for accuracy
What does ‘Sequentially’ mean in Summation of Force & what is it generally used for
Sequential combination of forces produced by different parts of the body, acting together to maximise force
- Used for throwing, kicking, or striking
Define ‘Projectile Motion’
A projectile is an object propelled into the air or water and affected only by the forces of gravity and air resistance.
What is the difference between Air resistance
& Gravity
- Without air resistance, a projectiles horizontal velocity would remain constant
- Downwards force which brings projectiles back to the ground (“what comes up, must come down”)
There’s 2 components causing the trajectory of a projectile what are they? & the difference between them
- Horizontal = Affected by air resistance and relates specifically to the horizontal distance covered by a projectile
- Vertical = Affected by gravity and relates specifically to the height reached by the projectile
The flight path of a projectile is determined by?
HAV
H = Height of release
A = Angle of release
V = Velocity/Speed of release
What is meant by the Height of Release
The greater the height of release of a projectile, the greater the horizontal distance it will cover, provided all other factors are equal.
What is the optimum height of release
Optimal angle of release is = 45⁰
What is the optimum height of release with a lowered position
Optimal angle of release is > 45⁰
What is the optimum height of release with a higher position
Optimal angle of release is < 45⁰
Define Angle of Release & what is the optimum angle of release
The angle of release of a projectile determines trajectory shape.
- Theoretical optimal angle of release for distance = 45⁰
An angle of greater than 45⁰ results in what?
- Shorter horizontal distances
- Greater vertical distances
- Longer flight times
An angle of less than 45⁰ results in what?
- shorter horizontal distances
- shorter vertical distances
- shorter flight times
Define Velocity/Speed of Release
The greater the speed or velocity of release, the greater the distance a projectile will carry.
The speed of release is the most important factor when maximising the distance travelled.
What does the Velocity of projectile at instant of release determine
height + length
Define ‘Balance’
Ability to neutralize forces that disturb the equilibrium
State the difference in Static & Dynamic Balance
-Static = Ability to hold a stationary position
- Dynamic = Ability to hold a moving position to execute an outcome
What does COG Center of gravity mean
Theoretical point in an object, located either inside or ouside of the body, where all of the body’s mass is equally distributed
What is the Line of Gravity
Imaginary line, passing downwards through the center of gravity to the ground or surface
