Definitions

• Momentum


  the amount of motion possessed by a moving body
• Momentum

  mass(kg) X velocity(m/s)
• Impulse


  the application of force over a period of time to change the momentum of an object
• Impulse

  force X time
• Conservation Of Linear Momentum


  the total amount of two objects before and after impact are equal
• Elasticity


  the ability of an object to return to its original shape after being deformed
• Coefficient Of Restitution 


  measures the elasticity of the collision between an object and a given surface
• Coefficient Of Restitution


  Height bounced/ height dropped or velocity after/ velocity before (square rooted)
• Angular Momentum


  the quantity of angular motion possessed by a rotating body
• Angular Momentum

  moment of inertia X angular velocity
• Moment Of Inertia


  the resistance of an rotating object to change its state of motion
• Moment Of Inertia

  mass of object X radius of rotation squared
• Conservation Of Angular Momentum


  when no external torque acts on an object, no change of angular momentum will occur
• Balence 


  the ability to neutralise forces that disturb equilibrium
• Centre of Gravity


  the theoretical point in an object, located either inside or outside the body, where all of the body's mass is equally distributed
• Line of Gravity


  an imaginary vertical line passing downwards from the centre of gravity to the ground or surface the person is on
• Base of Support

  the area bound by the outermost regions of contact between a body and support surface
• Segmental Interaction


  the transfer of energy/momentum across the joints of the body in the correct timed sequence to achieve the desired outcome for the task
• Fluid Mechanics


  the natural science of fluid in motion
• Turbulent Flow


  flow in which the velocity at any point varies erratically
• Laminar Flow


  a type of fluid flow in which fluid moves smoothly in individual layers or steams
• Boundary Layer Separation


  where the boundary layer breaks away from the ball
• Surface Drag


  friction produces between fluid and the surface of a moving object through said fluid
• Pressure Drag


  resistance created by the pressure differential between the front and back of an object moving through fluid
• Wave Drag


  the creation of waves forming resistance at the point where air and water interacts
• Buoyancy


  refers to the upward force that keeps things afloat
• Archimedes Principle


  states that the buoyant force acting on an object is equal to the weight of the fluid displaced by the object
• Lift


  refers to the component of force that acts perpendicular to the direction of flow
• Bernoulli's Principle


  relates to the pressure created from a moving fluid over an object, whereby fast flowing fluid produces a low pressure area and slow moving fluid produces a high pressure area
• Magnus Effect


  the term used to describe the effects of rotation on an object's path as it moves through a fluid
• Magnus Force


  the force causing an additional movement, which changes the flight path of a rotating object