Biomechanics Definitions Flashcards
Define force
A push or pull that alters the state of motion of a body
Define inertia
The resistance of a body to change its state of motion, whether at rest or while moving
Define velocity
The rate of change in displacement
Define momentum
The quantity of motion possessed by a moving body
Define acceleration
The rate of change in velocity
Calculation and units for velocity
Velocity = displacement ÷ time taken
• measured in (m/s)
Calculation and units for momentum
Momentum = mass × velocity
• measured in (kg/s)
Calculation and units for acceleration
Acceleration = (final velocity - initial velocity) ÷ time taken
• units - m/s/s
Calculation and units for force/weight
Force = mass × acceleration
Units - N (Newtons)
Define net force
The sum of all forces acting on a body, also termed resultant force
Define weight
the gravitational pull that the earth exerts on a body
Give the calculation and units for weight
Weight = mass × acceleration due to gravity
• units - (N)
Define friction
The force that opposes the motion of two surfaces in contact
Define air resistance
The force that opposes the motion through the air
Define streamlining
The creation of smooth air flow around an aerodynamic shape to minimise air resistance
What is a free body diagram
A clearly labelled sketch showing all of the forces acting on a body at a particular instant in time
Define reliability
The extent to which an experiment, test or measuring procedure gives the same results after repeated trials
Define validity
How well a test measures what it claims to measure. It is important for a test to be valid in order for the results to be accurately applied and interpreted
Define balanced force
When two or more forces acting on a body are equal in size and opposite in direction
Define unbalanced force
When two forces are unequal in size and opposite in direction
