The Description of Human Motion Flashcards
The act or process of changing place or positions with respect to some reference object.
Motion
True or false: motion is relative.
True
What instigates movement?
A force
What must the force be greater than to produce movement in an object?
The object’s inertia
What is inertia?
Resistance to motion
During linear/angular motion, the object is translated as a whole from one location to another.
Linear
During linear/angular motion, the object, acting as a radius, moves about a fixed point.
Angular
Three types of linear motion:
Rectilinear, curvilinear, circular
Rectilinear motion is a ________-_____ __________
straight-line progression
Curvilinear motion moves along a ___________ ________
curved pathway
Circular motion moves _________ ___ ______________
around the circumference
Angular motion is measured in __________.
degrees
Circular motion describes motion of ANY point on the radius, while angular motion describes motion of the ________ ________.
entire radius
Reciprocating motion is a ___________ ________.
repetitive movement
The term oscillation refers specifically to repetitive movements in an ___.
arc
The combination of linear and angular motion is called __________ ______.
general motion
Because most joints are axial, body segments primarily undergo __________ motion.
angular
Factors required for linear motion:
1.) Object must be free to move
2.) Force must be applied uniformly against one entire side of the object OR in line with the object’s center of gravity (in the case of excessive friction)
Factors required for rotary motion:
1.) One part of an object must be “fixed”
2.) Force must be applied on any portion of the object that is free to move
Levers produce _______ motion.
rotary
____________ motion is caused by a uniform repetition of opposing force applications.
Reciprocating
___________ is produced by repeated applications of gravitational force to a suspended object that is free to move back and forth in any position other than resting.
Oscillation
Three external factors that modify motion:
Friction, air resistance, water resistance
6 internal resistance factors that modify motion:
Friction in the joints, tension of antagonistic muscles, tension of ligaments and fasciae, anomalies of bone and joint structure, atmospheric pressure within the joint capsule, presence of interfering soft tissues.
Kinematics describes motion in terms of ___________, ________, and _____________.
displacement, velocity, acceleration
True or false: Kinematics can only be linear, not angular.
False
Linear velocity equation
V = s/t
When _________ is constant, the motion is said to be uniform.
Velocity
When velocity changes, its rate of change is called __________________.
acceleration
Linear acceleration equation
a = (vf - vi)/t
When the acceleration rate is constant, the velocity change is the same during equal time periods. Under these conditions, motion is said to be __________ _________.
uniformly accelerated
Example of uniformly accelerated motion
Free fall!
When air resistance is increased to an equal accelerating force of gravity, __________ ________ is achieved.
terminal velocity
Laws of Uniformly Accelerated Motion
Vf = Vi + at
s = Vit + (at)^2 / 2
Vf = Vi^2 + 2as
True or false: The time is takes for an object to rise to the highest point of its trajectory is equal to the time it takes to fall to its starting point.
True
An object that has been given an initial velocity and then allowed to move in free fall under the influence of gravity.
Projectile
Projectiles always follow the path of a __________.
Parabola
True or False: The greater the difference between release height and landing height, the lower the angle of projection needs to be.
True
What are the three factors that control projectile range?
1.) Speed of release
2.) Angle of projection
3.) Height of release
Angular displacement is calculated using _______, ________, or ________.
degrees, revolutions, radians
Angular velocity equation
w = θ/t
Angular acceleration equation
a = (wf - wi)/t
If the ______ velocity is kept constant, then the ______ velocity is proportional to the length of the lever.
Angular; linear
If the _____ velocity is kept constant, then an increase in radians will decrease the _______ velocity
Linear, angular
