Chapter 4: Kinetic Concepts of Human Movement 2

Question 1

General Motion

Answer 1

nearly all human movement

- Is a combination of linear or angular motion
- E.g. Running a 100m sprint

Question 2

Types of Motion

Answer 2

• Angular Motion
• Linear Motion
• Projectile Motion

Question 3

Angular Motion

Answer 3

rotation around a central axis or fixed point

• Seen in human limbs around joints
• E.g. bicep curl - humorous rotates around elbow joint
• Axis of rotation can be real or imaginary, external or internal

Question 4

Torque

Answer 4

force that creates angular motion by not acting through an objects center of gravity causing rotation

• Calculated by Torque = Force x Lever Arm
• Greater torque by applying force with a longer lever arm

Question 5

Lever Arm

Answer 5

distance from line of axis of rotation to the line of force

Question 6

Factors that increase torque

Answer 6

• size of force

- length of lever arm

Question 7

Angular Distance

Answer 7

measures the path from start to finish in degrees

Question 8

Angular Displacement

Answer 8

measures the change in position(initial to end position) in degrees

Question 9

Angular Speed

Answer 9

the angular distance covered / time taken in degrees/s

Question 10

Angular Velocity

Answer 10

the angular displacement / time taken in degrees / s

Question 11

Angular Acceleration

Answer 11

the change in angular velocity through (final velocity - initial velocity) / time in degrees/s2

Question 12

Projectile Motion

Answer 12

motion that any object or body possesses when released into the air

Question 13

Factors that influence Projectiles

Answer 13

• Gravity: a force working against vertical movement

- Air Resistance: a force working against the horizontal motion of a projectile

Question 14

Factors that Affect Flight Path

Answer 14

• Speed of Release(shorter release = shorter distance / longer release = longer distance)
• Angle of Release(usually released at an angle of 0-90 degrees but if starting higher than landing point an angle less than 0 might be used at)
• Height of release(higher than landing point = smaller angle of release/below the landing point = higher angle of release)

Question 15

Linear Motion

Answer 15

movement where all body parts move at the same speed in the same direction

Question 16

Types of Linear Motion

Answer 16

• Rectilinear: movement along a straight path

- Curvilinear: movement along a curved path

Question 17

Linear Distance

Answer 17

measures the path from start to finish

Question 18

Linear Displacement

Answer 18

measures the change in position(initial to end position)

Question 19

Linear Speed

Answer 19

Distance/time in m/s

Question 20

Linear Velocity

Answer 20

displacement / time in m/s

Question 21

Linear Acceleration

Answer 21

(Final Velocity - Initial Velocity) / time in m/s2

Question 22

Newtons 1st Law of Angular Motion

Answer 22

The angular momentum of a body remains constant unless acted upon by an external torque

Question 23

Newtons 2nd law of Angular Motion

Answer 23

A torque applied to an object will produce a change in angular motion in the direction and directly proportional to the size of the torque

Question 24

Newtons 3rd Law of Angular Motion

Answer 24

For every torque, there is an equal and opposite torque

Question 25

Angular Momentum

Answer 25

the amount of angular motion an object possesses

• Found by equation Angular motion = Angular velocity x moment of inertia
• angular momentum never changes

Question 26

Moment of Inertia

Answer 26

a measure of a body’s resistance to change in its rate of rotation

• Dependent on the mass of the object
• Dependent the distance the weight is distributed from the axis of rotation

Question 27

Conservation of Angular Momentum

Answer 27

angular momentum that is conserved when a body is in flight

• Best observed in diving
• When Angular momentum is being conserved, there is a trade off between angular velocity(how fast you spin) and moment of inertia(inversely proportionate)