Chapter 5 - Biomechanical Movement (Paper 2) Flashcards
Define linear motion.
Motion in a straight or curved line, with all body parts moving the same distance at the same speed in the same direction.
Define inertia.
The resistance an object has to a change in its state of motion.
What is Newton’s first law of inertia?
A force is required to change the state of motion. If an object is at rest, it will remain still. Similarly, if it is moving in one direction it will continue to do so at the same velocity until another force is exerted upon it. The bigger the mass, the larger the inertia of a body or object. This means that more force will be needed to change its state of motion.
What is Newton’s second law of acceleration?
The magnitude (size) and direction of the force determines the magnitude and direction of the acceleration.
What is the rate of acceleration directly proportional to?
Force causing the change.
How do you calculate Force?
Force = mass x acceleration (F=ma)
What is Newton’s third law of motion?
For every action (force) there is an equal and opposite reaction (force). This law describes what happens when two bodies (or objects) exert forces on one another. Action and reaction are equal and opposite and always occur in pairs. Action acts on one of the body’s and the reaction to this action acts on the other body.
What is the ground reaction force?
The equal and opposite force exerted on a performer who applies a muscular force on the ground.
What is scalar quantity?
When measurements are described in terms of just their size or magnitude.
Name some scalar quantities.
- Speed
- Distance
- Mass
- Temperature
What is not taken into account regarding scalar quantity?
Direction
How do you calculate speed?
Speed in metres per second (ms) = Distance covered in metres(m) / Time taken in seconds (s)
What is centre of mass?
This is the point of balance and the point of concentration of mass.
What is the line of gravity?
This is the line extending vertically downwards from the centre of mass.
What are the factors affecting stability? Explain them.
- 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 - often the greater the mass, the more stability there is because of increased inertia.
