Biomechanics Flashcards
Define law of inertia
A body continues in a state of rest or uniform velocity unless acted upon by an external or unbalanced force
Define law of acceleration
Body’s rate of acceleration is directly proportional to the size and the direction of the force applied
Define law of reaction
For every action force, there is an equal and opposite reaction force
What is Newton’s first law?
Law of inertia
What is Newton’s second law?
Law of acceleration
What is Newton’s third law?
Law of reaction
Which law is law of inertia?
Newton’s first law
Which law is law of reaction?
Newton’s third law
Which law is law of acceleration?
Newton’s second law
What’s the equation for velocity?
M/S
Velocity = displacement / time
What is velocity?
Rate of change in displacement
What do you call the rate of change in displacement?
Velocity
What is momentum?
The quantity of motion possessed by a moving body
what is momentum measured in?
Kgm/s
how do you calculate momentum?
momentum = mass X velocity
what is acceleration?
rate of change in velocity
what is acceleration measured in?
m/s/s or m/s²
how do you calculate acceleration?
(final velocity - initial velocity) / time taken
what is force?
push or pull that alters the state of motion of a body
what is force measured in?
Newtons
how do you calculate force?
force = mass X acceleration
what is an internal force?
a force that is generated by contraction of skeletal muscle
what is an external force?
a force that comes from outside the body
what do you call a force that is generated by the contraction of skeletal muscle?
internal force
what do you call a force that is generated by something outside the body?
external force
what do we also call the net force?
resultant force
what is net force?
the sum of all forces acting on a body when all individual forces have been considered
when would the net force of a body be 0?
when it is at a constant velocity or at rest
what is a positive force?
acceleration
what is a negative force?
deceleration
what can forces do?
create motion
cause acceleration
cause deceleration
change direction
change shape
what is the definition of weight?
the gravitational pull that Earth exerts on a body and is measured in Newtons
what is weight measured in?
Newtons
how do you calculate weight?
weight = mass X acceleration
N = Kg X m/s/s
what is reaction force?
equal and opposite force exerted by a body in response to the action force placed upon it
in what direction does reaction force act?
it always acts upwards
vertically
what are the vertical forces?
weight
reaction force
what are the horizontal forces?
friction
air resistance
what is friction measured in?
Newtons
what is friction?
friction occurs when 2 surfaces slide over each other
acts in the opposite direction to motion
acts parallel to the 2 surfaces in contact
drawn in the same direction as the motion
what factors impact friction?
roughness
temperature
size of reaction
what is air resistance measured in?
Newtons
what is air resistance?
the forces that oppose motion of a body travelling through the air
it is a form of fluid friction
measured in Newtons
which factors impact air resistance?
-velocity
-shape
-frontal cross sectional area
-smoothness of the surface
when do you get a balanced force?
when the net force of a body is 0
what is a sporting example of a balanced force?
a football on a penalty spot before the force of it being kicked is applied
