Linear/Angular Motion

Question 1

What is kinematics?

Answer 1

Study of characteristics of motion

-Spatial and temporal

Question 2

Why do we study kinematics?

Answer 2

Understand motion: joint movements and planes of motion
Optimise performance/ function
Minimise injury risk

Question 3

How do we study kinematics?

Answer 3

Observation: 2D and 3D

Question 4

How are scalars described?

Answer 4

By their magnitude:
Distance
Speed
Volume

Question 5

How are vectors described?

Answer 5

By their magnitude and direction:
Displacement
Velocity
Acceleration

Question 6

What is a vector?

Answer 6

Shortest distance from origin/ length of straight line joining initial and final positions

Question 7

What is distance?

Answer 7

Length of path travelled

Question 8

Speed equation

Answer 8

Time

Question 9

Velocity equation

Answer 9

Displacement D
—————– = —
Time T

Question 10

What is velocity?

Answer 10

The rate of change in displacement with respect to time

Question 11

Velocity units

Answer 11

M/s

Question 12

What is differentiation?

Answer 12

The Mathematical process that quantifies the rate of change in one variable with respect to another

Question 13

What is instantaneous velocity?

Answer 13

The change in displacement with respect to time

Question 14

What is equal to the gradient/slope of the displacement-time curve?

Answer 14

Differentiation

Question 15

Integral of velocity = ?

Answer 15

Displacement

Question 16

What is integration?

Answer 16

Quantities the total change of one variable with respect to another (reverse process of differentiation)

Question 17

What is acceleration?

Answer 17

The rate of change in velocity with respect to time

Question 18

Acceleration equation

Answer 18

T

Question 19

Acceleration units

Answer 19

M/s2

Question 20

What is an angle?

Answer 20

Composed of two lines that intersect at a point called the vertex

Question 21

What is a relative angle?

Answer 21

Included angle between the longitudinal axes of two segments (joints)

Question 22

What is an absolute angle?

Answer 22

Angle of inclination (orientation) of a body segment in space

Question 23

What are the 3 units to measure angles?

Answer 23

Degrees
Revolution
Radian

Question 24

Define degrees

Answer 24

Circle (describes rotation) transcribes an arc of 360*

Question 25

What is a revolution?

Answer 25

*useful in qualitative analysis, performance descriptor | 360* = 1 revolution

Question 26

Define radian

Answer 26

The measure of an angle at the centre of a circle, described by an arc equal to the length of the radius of the circle

Question 27

360* = 1 revolution = ?? Radians

Answer 27

2pie radians

Question 28

Degrees to radians

Answer 28

Divide by 57.3

Question 29

Radians to degrees

Answer 29

Multiply by 57.3

Question 30

Radians =

Answer 30

Degrees x pie ---- 180

Question 31

Degrees =

Answer 31

Radians x 180 ------- Pie

Question 32

What is the right hand rule?

Answer 32

Curled fingers indicate direction of rotation | *thumb points in the direction of the angular velocity vector

Question 33

What is polarity?

Answer 33

Refers to the direction of rotation of angular motion Counter-clockwise: +ve polarity Clockwise : -ve polarity

Question 34

What is angular distance?

Answer 34

Total of all angular changes of rotating object

Question 35

What is angular displacement?

Answer 35

Difference between the initial and final positions of the rotating object

Question 36

What is angular speed?

Answer 36

Defined as angular distance travelled per unit of time

Question 37

What is angular velocity?

Answer 37

Defined as change in angular displacement relative to change in time

Question 38

Angular speed equation

Answer 38

Angular distance ------------------- Time

Question 39

Angular velocity equation

Answer 39

Angular displacement -------------------------- Time

Question 40

Angular velocity units

Answer 40

rad.s*1

Question 41

What is angular acceleration?

Answer 41

The rate of change in angular velocity over time

Question 42

Angular acceleration equation

Answer 42

w ---- T

Question 43

Angular acceleration unit

Answer 43

rad.s*2

Question 44

What is angular-linear motion?

Answer 44

In many human movements, motions of the segments constituting the movement are ANGULAR -- resulting movement is LINEAR

Question 45

Tangential velocity

Answer 45

.. Of the ball is dependent upon the length of the arm segment and its angular velocity

Question 46

Tangential velocity equation/unit

Answer 46

V t = r. w M.s*1

Question 47

Tangential acceleration

Answer 47

... Of the bowling ball is dependent upon the length of the arm segment and its angular acceleration *a vector tangent that is perpendicular to the rotating segment

Question 48

Tangential acceleration equation/unit

Answer 48

a T = r a M.s*2