Angular Kinetics

Question 1

Why would a diver open up as they approach the water?

Answer 1

To slow down their angular velocity

Question 2

To learn how body position affects motion we must examine what components?

Answer 2

Angular kinetics to examine the torques that affect rotational movements

Question 3

What is a torque?

Answer 3

A force that produces rotation (movement of force). Also known as a moment or rotational force.

Question 4

What are the 3 factors that a torque is dependent on?

Answer 4

The magnitude of the force
Point of application
Direction

Question 5

What is the formula for torque? The units?

Answer 5

T=Fd

Units: Nm

Question 6

What is d (perpendicular) in regards to torque?

Answer 6

(Moment arm) or the perpendicular distance between the line of action of the force and the axis of rotation

Question 7

What is Newtons 1st Law? (For linear motion…)

Answer 7

Every body remains in a state of constant velocity unless acted upon by an external force.

Question 8

What is the angular equivalent?

Answer 8

Every body remains in a constant rotational state unless acted upon by an external torque.

Question 9

A system will continue to rotate with a constant ____ until acted upon by a _____.

Answer 9

angular momentum

momentum of force

Question 10

A system will resist a change in its ______.

Answer 10

angular state of motion

Question 11

What is the momentum of inertia?

Answer 11

Movement= dealing with rotation

Question 12

Formula for Inertia?

Answer 12

I=mk2

Question 13

What is (k) the radius of gyration?

Answer 13

The distance from the axis of rotation to where body mass is concentrated. (Angular equivalent of mass).

Question 14

What happens when a body is more tightly concentrated

Answer 14

the radius of gyration will be smaller in the pike position

Question 15

The moment of inertia affected by _____ and ______?

Answer 15

Body orientation

Segment orientation

Question 16

What happens when the body is fully extended when measuring Inertia?

Answer 16

The radius of gyration will be larger in the layout position

Question 17

What are the principal moments of Inertia? (Relative planes of Inertia).

Answer 17

Transverse planes
Sagittal Plane
Frontal Plane

Question 18

Inertia is low in what plane of Inertia?

Answer 18

Transverse Plane

Question 19

Moderate Inertia takes place in what plane?

Answer 19

Sagittal Plane

Question 20

Inertia is highest in what plane?

Answer 20

Frontal Plane

Question 21

What is Newtons Second Law?

Answer 21

The law of momentum and the law of acceleration. (Linear motion and Angular Equivalent).

Question 22

Newtons Second Law: For Linear Motion for the law of momentum?

Answer 22

The rate of change of momentum of a body (or the acceleration for a body of constant mass) is proportional to the force causing it and the change takes place in the direction in which the force acts.

Question 23

Newtons Second Law: The Angular Equivalent for the law of momentum?

Answer 23

The rate of change of angular momentum of a body is proportional to the torque (moment) causing it and the change takes place in the direction in which the torque (moment) acts.”

Question 24

Newtons Second Law: For linear Motion for the law of acceleration?

Answer 24

A force applied to a body causes an acceleration of that body of a magnitude proportional to the force, in the direction of the force, and inversely proportional to the body’s mass.

Question 25

Newtons Second Law: For Linear motion for the law of acceleration?

Answer 25

A net torque produces angular acceleration of a body that is directly proportional to the magnitude and inversely proportional to the body’s moment of inertia.

Question 26

When an object rotates it has ________.

Answer 26

Angular Momentum= the quantity of motion

Question 27

What is the formula for Angular Momentum?

Answer 27

(H)= moment of Inertia * angular velocity

H=Iw

Question 28

What are the units for angular momentum?

Answer 28

Units: kg m2/s

Question 29

According to Newtons 1st law, in the absence of an external torque, every system remains in what kind of state?

Answer 29

Constant rotational state

Question 30

When the total angular momentum of the body is conserved, the ________ will affect how the system moves in the air.

Answer 30

Body Position

Independently moving the arms can shift the axis of rotation

Question 31

What are Asymmetrical movements?

Answer 31

Compensatory movements

Initial Movement

Question 32

What is a compensatory movement?

Answer 32

Kicking the legs forward to cause the body to rotate backwards.

Question 33

What is an Initial Movement?

Answer 33

Swinging the arm at the shoulder joint to cause the whole body to rotate forward.

Question 34

What is the local term when calculating Angular Momentum?

Answer 34

Examining the momentum of an individual segment of the system

Question 35

What is the remote term when calculating Angular Momentum?

Answer 35

Examining the momentum of the entire system

Question 36

In order to change the angular momentum of a system, we need to apply a _______ over a period of _________.

Answer 36

Torque

Time

Question 37

Angular Impulse formula?

Answer 37

Angular Impulse= Torque* time

Question 38

Units for Angular Momentum?

Answer 38

Units: Nms

Question 39

For Linear Motion:

Answer 39

For every force applied by one body on a second, the second body applies an equal and oppositely directed force on the first

Question 40

For Angular Equivalent:

Answer 40

For every torque (moment) applied by one body on a second, the second body applies an equal and oppositely directed torque (moment) on the first