Glossary

Notational Analysis

This is what is used to analyse performance of either an individual or team. This is when you look at different techniques and tactics of a performer, this data is then recorded and is used in following matches to improve performance as well as to gain advantage over the opposition. Athletes and coaches use this to identify strengths and areas for improvement.

Performance Criteria

There are different performance criteria’s for different sports. This is basically a list of factors that are needed to aid as well as improve your sporting performance such as, shot and pass accuracy, rebounds and successful catches.

Numerical Model

A numerical model is a model that uses numbers to obtain the behaviour over a long period or set period of time.

Linear Motion

Linear motion involves vector, which is a measurement in a certain direction, scalar this is a simple measurement which has no direction. Within linear there are many different quantities these include speed, velocity, displacement, acceleration and can be distance.

 

Linear velocity is when we measure the rate at which an object changes position, the equation is:

 

Velocity (m/s¹) + displacement (change in position) ÷ time.

 

Acceleration is the rate at which that velocity changes, the equation is:

 

Acceleration (m/s²) = change in velocity (V_f – V_i ) ÷ time taken (t).

Angular Motion

Within angular motion the different quantities are displacement, acceleration and velocity. Velocity is the rate at which the angular displacement changes and can be described as the speed of rotation, the equation is:

 

Angular velocity (ω) = angular displacement (θ) ÷ time (t).

 

Acceleration is the rate at which the angular velocity changes, and the equation is:

 

Angular acceleration = change (∆) in angular velocity (ωf – ωi) ÷ time (t). Displacement is a change in position from the starting position: Displacement = Velocity x Time

Inertia

This is an objects resistance to move and is determined by the mass of the object. But when it comes to angular motion this resistance to movement is due to not only the mass of the object but also where this mass is located.

An example is an Olympic high diver when they come to do a summersault where they tuck themselves in to reduce their inertia meaning their body is then able to rotate faster. But when they come to straighten their body when they enter the water this will increase their inertia and slow down the rotation of their body. Inertias units are kgm². When we look at the equation we see that looking at the distance most of the mass comes from the axis of rotation and has more of an effect on angular inertia than the objects actual mass.

Moment of inertia = mass of any particle within the object × (distance from the particle to the axis of rotation) ²

Centre of Mass

This is an imagery point where the mass of an object is considered to act. All objects are able to balance at their centre of mass point, the centre of mass can lie outside of the body. When it comes to humans their centre of mass lie a metre into their body meaning it can be found just above the waist. When we think about the location of the centre of mass this is determined by the shape of the body and if the body moves, this will shift the centre of mass. An example is when an athlete bends their legs this then lowers their centre of mass and results in a greater stability. If a ridged or misshaped body went through the air the centre of mass would form a parabolic arc.

Projectile Motion

When we launch ourselves or an object like a javelin into the air this is called a projectile. A projectile is a subject that only uses the forces of both gravity and air resistance.

A projectiles flight and trajectory is affected by different mechanical principles, including, the angle at which it was released, the height it was released at, the velocity it was released at and also the angle of attack.

Parallax Error

This is a displacement or the difference in the position of a certain object this can be seen through different lines of sight. Parallax errors are measured by either the angle or semi-angle of disposition between those two different lines. An error can occur when the scale is too thick or it is above or below the scaled as well as when our vision isn’t perpendicular to the scale, this means you will get a different reading or result to those looking at it from a different angle.