Angular motion

• Biomechanics

  The study of the mechanical aspects of biological systems
• Motion

  Angular and linear motion
• Law of inertia

  The body will remain at rest or in constant uniform motion unless a force acts upon it
• Law of inertia

  • A tackle in football, a penalty
• Law of acceleration

  The rate of change in momentum of an object is directly proportional to the force applied to it and in the same direction as its application
• Law of acceleration

  • Kicking the ball, force distance
• Law of reaction

  Every action has an equal and opposite reaction
• Law of reaction

  • Running along the pitch, force applied to the ground is everted back pushing the athlete along the pitch, ground reaction force
• Force-Time Graphs

  The area of the graph is impulse, which is force x time
• Positive impulse, negative impulse, net impulse, zero net impulse
• The graph shows acceleration when the performer is accelerating, e.g. start of a sprint, push off
• The graph shows the performer maintaining speed at constant velocity
• The graph shows the performer decelerating, e.g. the end of a race, decrease in velocity
• Motion

  Change in location/position of an object with respect to time
• Force

  Required to create motion
• Internal forces

  Produced by concentric muscle contraction, from animate objects
• External forces

  Gravity, friction, reaction, air/water resistance
• Linear motion

  Straight-line movement of an object segment, where all parts move in the same direction and at the same speed
• Mass

  The quantity of matter in the body
• Weight

  Force of a given mass due to gravity
• Momentum

  Mass x velocity
• Acceleration

  Change in velocity over time
• Force

  Mass x acceleration (m/s²)
• Vector quantity

  Has magnitude and direction
• Scalar quantity

  Has magnitude only
• Distance

  Overall ground covered
• Displacement

  Distance between starting point and finishing point
• Speed

  How fast an object is moving
• Velocity

  The rate at which an object changes its position
• Velocity-time graph: area under the line is displacement
• Acceleration

  The rate at which velocity changes with respect to time
• Momentum

  Mass x velocity, a measure of an object's motion
• Angular motion

  Rotational movement of a body segment or entire body around an axis/point
• Angular momentum

  The movement of a mass around an object, calculated by multiplying angular velocity with the moment of inertia
• Angular velocity

  How quickly an object/human rotates
• Moment of inertia

  The resistance of an object to rotate, the rotational equivalent of mass
• Angular displacement

  The angle through which a segment has rotated, measured in degrees or radians
• 1 radian = 57.29578 degrees
• Angular acceleration

  The rate at which angular velocity changes over time
• There is a conservation of angular motion