biomechanics Flashcards
biomechanics
The mechanical concepts applied to the human body and function
Includes the forces and the motion produced
force
Force = magnitude of push or pull action (F = Mass x Acceleration)
scalar
Scalar = describes only magnitude (how much) (i.e., ounces, grams, kilos)
vector
Vector = Measure of Magnitude (how much) and direction (of the push/pull)
Force is a Vector
mass
The amount of matter a body contains
How big something is
kinetics
Kinetics describes what causes motion
torque
Torque = force that produces rotation around an axis
ex) a hammer pulling a nail out
ex) doing a bicep curl
friction
Friction = force between two surfaces. Attempts to prevent motion of one surface over another
ex) a runners shoes create friction
velocity
Velocity = force + speed
law of inertia
Law of Inertia = an object in motion wants to stay in motion, an object at rest wants to stay at rest.
Need to generate enough force to get the object out of state of inertia
The greater the mass, the more force is needed to change the inertia
law of inertia
Objects as rest will stay at rest until force is applied.
Objects in motion will stay in motion until force is applied.
Ball Example
Seat belt example
law of acceleration
Law of Acceleration = the amount of acceleration (increasing speed/velocity) depends on the strength of the force applied to the object.
The amount of acceleration is proportionate to the amount of force applied.
The greater the mass, the more force needed to achieve the same acceleration as something with a smaller mass
Acceleration
Any change in velocity of an object
Kick a ball and see how far it travels.
Kick it twice as hard and it should go twice as far.
When the ball starts moving, it is accelerating.
If you were to kick it even harder, it would travel proportionately farther.
More force= more acceleration proportionate to that force
The amount of acceleration depends on…
The amount of acceleration depends on the strength of the force applied.
acceleration and direction
Acceleration can also deal with change in direction.
Force is needed to change direction.
Change in direction depends on the force applied (ie amount of force and direction of force)
If you were to apply the same force to two objects of differing mass, the object with the greater mass will…
If you were to apply the same force to two objects of differing mass, the object with the greater mass will accelerate less.
Acceleration is proportionate to the mass of an object
Law of Action-Reaction
Law of Action-Reaction = for every action, there is an equal and opposite reaction