By Danni Pearce Zedi Hodgson. Chapter five; biomechanical principles of motion through air and water. By Danni Pearce Zedi Hodgson.

Biomechanical principles definition; The study of the action of external and internal forces on the living body, especially on the skeletal system.

Projectile motion; Vertical and horizontal components. Angle of projection. Speed of release. High of release. projectile motion definition: Projectile motion refers to the motion of an object projected into the air at an angle. A few examples of this include a soccer ball begin kicked, a baseball begin thrown, or an athlete long jumping. Even fireworks and water fountains are examples of projectile motion.

Vertical and horizontal components; Horizontal component definition: the horizontal component determines how far an object will travel. Example: Vertical component definition: the vertical component determines how high an object will travel. Example: if you drop one ball and through another ball from the same height at the same time they will both hit the ground at the same time because they have the same vertical component of motion.

Factors affecting the path of projectile; Angle of projection; The angle of projection is the angle at which an object is released into the air. Speed of release; The speed at which an object is thrown, kicked or propelled into the air is referred to as the speed of release. Height of release; the height of release is the difference between the height that a projectile is released and the height at which it lands or stops.

Human movement through air and water; Laminar and turbulent flow. Buoyancy. Drag force. Lift force.

Laminar and turbulent flow; An object moving through a fluid medium such as air or water with a relatively low velocity will not disturb the flow of the fluid very much. Eg consider a swimming moving though the water. Their hands move slowly through the water and don’t disturb the layers of the fluid very much.

Buoyancy; Is a force that acts vertically upwards on a body that is Immersed in water. Eg this means it is easier to float in the ocean than in a freshwater lake.

Drag force; Drag force is generated when a fluid flows around a stationary object or when an object moves through a fluid. Eg is a tennis ball I throw it has a greater turbulence and if a bike helmet thrown I has less turbulence because its flatter.

Lift force; Is generated when a body or object moves through air or water. Eg the shape of an object determines the amount of lift force that can be generated. Foil shapes generate greater amount of lift.

Chapter six; biomechanical principles of force production.

Definition. Inertia; Mass and weight; Definition: mass= The amount of matter that makes up an object. Weight= The measure of gravitational force acting on a body. Definition: The tendency of an object to resist change in its state of motion. Forces; Definition: A push or pull acting on a object.

Examples; Intertia: a wet football requires greater force to move it a set distance then a dry football because as the ball becomes waterlogged the mass increases. Mass and weight: a smaller less muscular person would not be able to bench press as much as a larger more muscular person. forces: the force absorbed by a baseball glove when a ball is caught correctly prevent the player getting hurt by the impact of the ball.

Newtons laws of motion; Newtons first law: A body will remain at rest or continue in a state of constant motion unless acted upon by an external force Example; Newtons First Law Newtons second law: a force applied to an object will produce a change in motion in the direction of the applied force that is directly proportional to the size of the force. Example: Newtons Second Law

Newtons Third Law: For every action there is an equal and opposite reaction. Example: Newtons Third Law

Types of forces; There are numbers of different external forces that act on the body such as gravity, weight, friction and air, and water resistance. Friction is a force that occurs when two surfaces come in contact with eachother.

Momentum; Momentum definition: is the measurement of the amount of motion that an object has. Conservation of momentum: momentum is conserved in an isolated system, which is one where there are no external forces acting. Angular momentum: the quantity of angular motion of an object. Conservation of angular momentum: angular momentum is conserved when the body is in flight. Summation of momentum: the sequential and coordinated movement of each body segment to produce maximum velocity.

Impact; Impact definition: a collision between two objects. Coefficient of restitution: a measure of elasticity of bodies involved in a collision.