Angular Kinetics Review Flashcards

Flashcards to review angular kinetics concepts, including center of gravity, stability, moment of inertia, angular momentum, and centripetal force.

What is the Center of Gravity (CG/COG)?

A point around which the weight of a body is balanced in all directions; also known as the Center of Mass (CM/COM).

Where can the location of the Center of Gravity be?

Inside or outside the object.

What is an advantage of the Reaction Board Method for CG location in the human body?

Simple.

What is a disadvantage of the Reaction Board Method for CG location in the human body?

Cannot be used with continuously changing body posture.

What is an advantage of the Segmental Method for CG location in the human body?

Body posture can change continuously; can be used in locating a continuously moving COM.

How is the whole body CG computed in the Segmental method?

From the segmental CG’s.

What is Stability?

Resistance to disruption of equilibrium; a mechanical concept.

What is Balance?

Ability to control equilibrium.

What is the Base of Support (BOS)?

Area bounded by outermost regions of contact between a body and support surfaces.

What factors affect stability?

Body mass and size of the base of support.

How does body mass impact stability?

Greater body mass increases stability.

How does the size of the base of support affect stability?

A larger base of support increases stability.

How does the horizontal position of the CG affect stability?

The closer the CG is to the base of support, the greater the stability.

How does the vertical position of the CG affect stability?

A lower vertical position of the CG increases stability.

What is Moment of Inertia (MOI)?

The inertia of an object in angular motion; the tendency of an object to maintain the current state of angular motion. Unit: kg·m2

What is the MOI of an Object?

Function of mass distribution about the axis of rotation.

What is Radius of Gyration (ROG)?

Distance from the axis of rotation to a point where the body’s mass could be concentrated without altering its rotational characteristics (MOI).

What does Radius of Gyration reflect?

The degree of mass dispersion from the axis.

Is MOI/ROG of the human body posture-dependent?

Yes

Torque = MOI * _?

angular acceleration

What is Angular Momentum?

Quantity of angular motion (vector). Unit: kg·m2/s

What is the formula for Angular Momentum?

AM = (MOI)(angular velocity)

What is Angular momentum conservation?

In the absence of external torque, total angular momentum of a system remains constant.

What is Angular momentum transfer?

Overall H remains constant but H of each body part may change.

What is Centripetal Force?

Force directed toward the center of rotation for a body in rotation.