biomech deck Flashcards
what is newtons first law
“A body continues in a state of rest or moving with constant velocity in a straight line, unless acted upon by an external force.”
what is newtons second law
“When a force acts on an object, the rate of change of momentum experienced by the object is proportional to the size of the force and takes place in the direction in which the force acts.”
what is newtons third law
“For every action, there is an equal and opposite reaction.”
what is centre of mass
The point where the mass of the body tends to be concentrated and balanced in all directions.”
what does The centre of mass depend on
The body position
The athlete’s body itself (shape)
Gender
A stable body position will enable an athlete to…
resist motion
The stability of an athlete is determined/ affected by:
The mass of the body
Size of the base of support
Height of the centre of mass
No. of points in contact with the surface
Proximity of the line of gravity to the centre of the base of support
equation of force
Force = Mass x Acceleration (F=Ma)
force is defined as
A push or pull that alters the state of motion of a body.
Force is essential to create motion and can do the following 5 things:
Create motion Accelerate a body Decelerate a body Change the direction of a body Change the shape of a body
net force definition
The overall force acting on
a body when all individual
forces have been considered.
balanced forces definition
Balanced Forces: When two or more forces acting on a body are equal in size
unbalanced forces definition
Unbalanced Forces: When forces acting on a body are unequal in size.
vertical forces
Weight & Reaction Force
horizontal forces
Friction & Air Resistance
define weight
Gravitational force that the Earth exacts on the body (Downwards).
define reaction force
Whenever there is a point of contact between two bodies, there will always be a reactionary force.
define air resistance
This is the force that opposes motion of a body travelling through the air.
define friction
The force that opposes the motion of two surfaces in contact. Measured in Newtons (N).
how can friction be affected
Roughness or smoothness of footwear or object in contact with the ground.
Roughness or smoothness of the ground or court.
Size of the down force (Think about N3)
Temperature of Surface – Depending on the characteristics of the bodies in contact.