Flashcards in Section 5: Biomechanical movement Deck (11):
What is Newton's first law of motion
Law of inertia - An object will be at rest until an external force is applied.
If an object is stationary or moving at a constant speed, it will need another force to change its state.
What is Newton's second law of motion
Law of acceleration - The rate of acceleration is directly proportional to the force causing the change.
Dependant on mass, the more force applied will mean that there is more acceleration.
What is Newton's third law of motion
Law of action and reaction - For every force applied there is an equal reaction force.
Sprinter pushes on the blocks and there is a force pushing back which is the reaction.
What is speed and how would you calculate it
The rate of change of position.
Speed = Distance/Time
What is the difference between a scalar and vector quantity
Scalar only takes into account the size/magnitude where as vector also takes into the account of direction.
What is distance
The length of the path a body follows when moving from one position to another.
What is the centre of mass
This is the point of balance. This can change dependant on body shape and size. lifting your arms would mean that your centre of mass would be higher.
What are the four factors that can affect stability
The height of the centre of mass - Lowering the centre of mass will increase stability.
Position of the line of gravity - Should be central over the base of support to increase stability.
Area of the support base - The more contact points the larger the base of support becomes and the more stable they become.
Mass of the performer - The greater the mass the more stability there is. This is because there is more inertia.
What is a first class lever. Give an example and sate mechanical advantages and disadvantages
The fulcrum is located between the effort and the load.
Example - This is when there is flexion and extension at the head or extension at the elbow.
Mechanical advantage - Large range of movement and any resistance can be moved quickly
Mechanical disadvantage - Cannot apply much force to an object.
What is a second class lever. Give an example and sate mechanical advantages and disadvantages
The load lies between the fulcrum and the effort
Example - Plantar-flexion at the ankle
Mechanical advantage - Can generate much larger forces. Has to lift the whole body weight
Mechanical disadvantage - Slow, with a limited range of movement.