Biomechanics Flashcards
define linear motion
Linear motion simply means motion in a straight line, there is no rotation and all body parts move in the same direction at the same speed
name an example of linear motion
a badminton drives it goes in a straight line
E.g. An ice skater gliding after they completed a movement or a cyclist who stops pedaling (straight line motion)
define speed velocity and and acceleration and how they relate to linear motion
speed: the rate at which someone or something moves or operates or is able to move or operate
velocity: is a vector (meaning it is measured in magnitude and direction) a definition for velocity is that it is speed with direction. instantaneous velocity is known is the average velocity the formula for velocity is displacement over the time taken. Velocity is measured in distance over time.
acceleration: The rate in which the velocity changes in a certain amount of time the formula for acceleration is change in velocity over the amount of time. Acceleration is measured in meters per second^2. the opposite of acceleration is deceleration foe example at a certain period when the shuttle cock is about to hit the ground and it is decelerating the shuttle cock may be flying at 0.6 meters per second^2
what is angular motion
motion on a rotational axis
what is newtons fists law
a body will continue in its state or uniform in motion unless acted on by another force
what is newtons second law and the formula
F= mxa
if you want too hit a object with higher acceleration you must hit it with more force as the object has constant mass
the large forces must be absorbed by the body for example when you catch a netball therefor it is important that the force is absorbed in the most appropriate way for example flexing at the knee when catching a netball
what is newtons 3rd law
that every action has an equal and opposite reaction for example when jumping to catch a netball the foot push against the ground this will mean the ground will push back with an equal and opposite force
what is general motion and an example
general motion is is linear and angular motion combined an example off this is a kick in soccer the run up is linear motion and the trunk rotation is linear velocity and the rotation of the thigh and the leg is angular motion
what is simultaneous movement and when is it used
often in accuracy based sports all the movements off the body will occur at the same time an example of this is a netball shot
what is sequential movement and what is it used for
sequential movement the movements will summate and will go one after each other the just before one body part deaccelerates the next body part will move this is summation of forces and will insure maximum velocity and distance
how does summation of forces occur
simultaneously and sequentially the forces will summate to achieve either accuracy of maximum velocity
1 the stronger and the larger muscles will move first and then the slower faster muscles
2 sequentially moving moving each body part to achieve optimum momentum
3 using as many body parts as possible so more forces is applied
4 one segment will move just before the presiding limb deaccelerates
what is projectile motion
A projectile is an object propelled into the air or water and affected only by the forces of gravity and air resistance
why is timing important when summating forces
because each body part should be increasing the velocity and the momentum should be transferd to the next body part as the time goes and if the body parts move too early or too late maximum velocity will not be obtained
explain air resistance and gravity
Air resistance
Without air resistance, a projectiles horizontal velocity would remain constant
Important in sports like discus, javelin, golf where air resistance affects the aerodynamic characteristics of the projectile
Gravity
Downwards force which brings projectiles back to the ground (“what comes up, must come down”)
Causes objects to accelerate towards the earth at a rate of 9.81m/s2 and is responsible for giving projectiles their parabolic flight path – without gravity a projectile keeps going forever!
what is a trajectory
The path of a projectile is referred to as its trajectory
