Biomechanical principles and use of technology Flashcards
What does Newtons 1st Law of Inertia state?
Body continues in a state of rest of uniform velocity unless acted upon by an external or unbalanced force
What does Newtons 2nd Law of Acceleration state?
A body’s rate of change of momentum is proportional to the size of the force applied and acts in the same direction
What does Newtons 3rd Law of Reaction state?
For every action there is an equal and opposite reaction
Define velocity and state its calculation
Rate of change of displacements
Displacement / time taken (m/s)
Define momentum and state its calculation
Quantity of motion possessed by a moving body
Mass x velocity (kg/m/s)
Define acceleration and state its calculation
Rate of change of velocity
(final velocity - initial velocity) / time take (m/s/s)
Define force and state its calculation
A push or pull that alters the state of motion of a body
Mass x acceleration (N)
What does a force do?
Creates motion
Decelerate/accelerate a body
Change shape/directional of the body
What is a net force?
Sum of all forces acting on a body
What does it mean for the net force to be 0?
No change in motion as forces are balanced
What is weight?
Gravitational pull that the earth exerts on a body
Mass x acceleration
What is reaction?
Equal and opposite force exerted by the body in response to an action force place upon it
What is friction?
Forces that opposes the motion of two surfaces in contact
What factors affect friction?
Roughness of ground surface
Roughness of contact surface
Temperature
Size of normal reaction
What is air resistance?
Force that opposes motion through air
What factors affect air resistance?
Velocity
Shape
Frontal cross sectional area
Smoothness of surface
What is the centre of mass?
The point at which an object is balanced in all directions. As a person raises their arms, the COM raises upwards
What is stability?
The ability of the body to resist motion and remain at rest.
Being able to withstand a force applied and return to its original position without damage.
What factors affect stability?
Mass of body
Height of COM
Size of base of support
Line of gravity
What makes up a lever?
Lever = bone
Fulcrum = joint
Effort = muscular force
Load = weight or resistance
What is a 1st class lever?
EFL or LFE
What is a 2nd class lever?
ELF or FLE
What is a 3rd class lever?
LEF or FEL
What is the effort arm?
Distance from the fulcrum and effort
What is the load arm?
Distance from the load and fulcrum
What is mechanical advantage?
The effort arm is longer than the load arm. A large load can be moved with a small effort. (2nd class lever)
What is mechanical disadvantage?
The load arm is longer than the effort arm. A large effort moves a small load. (3rd class level)
What is limb kinematics?
Studies the movements of limbs
Put reflective markers on the performers bond landmarks. They are filmed and the data is transferred into a digital format.
Advantages of limb kinematics
Data immediately available
Changes can be made to techniques
Examine causes of injury
Disadvantages of limb kinematics
Expensive
Requires lab conditions
What is a force plate?
A platform that measures all of the forces applied when a performer stands, steps or jumps on it. Measures ground reaction
Advantages of force plates
Fast and accurate results
Analysis of gait
Results useful to plan development programme
Disadvantages of force plates
Expensive
Require lab conditions
What is a wind tunnel?
A chamber through which air is flowed through
Advantages of wind tunnels
Adapt equipment and techniques
Mimics wind conditions
Disadvantages of wind tunnels
Expensive
