Equilibrium, Stability & Balance

Question 1

Define Equilibrium?

Answer 1

A body is said to be in equilibrium when the resultant of all forces acting upon it is zero.

Question 2

At which point are all objects at rest in equilibrium?

Answer 2

All forces acting on them are balanced.
The sum of all linear forces equals zero.
The sum of all torque equals zero.

Question 3

What are the 3 types of equilibrium?

Answer 3

Stable.
Unstable.
Neutral.

Question 4

Explain when stable equilibrium occurs?

Answer 4

Occurs when an object is placed in such a fashion that an effort to disturb it would require its centre of gravity to be raised.

Question 5

Explain when unstable equilibrium occurs?

Answer 5

The centre of gravity of the object drops to a lower point when the object is tilted.

Question 6

Explain when neutral equilibrium occurs?

Answer 6

Occurs when an object comes to rest in a new position without a change in the level of the centre of gravity after being displaced.

Question 7

Define Stability?

Answer 7

The resistance to disturbance of equilibrium.

Question 8

What are the 8 factors that effect stability?

Answer 8

The size and shape of the base of support.
The line of gravity to the base of support.
The height of the centre of gravity.
Mass of the body.
Friction.
Segmentation Alignment.
Visual and psychological factors.
Physiological factors.

Question 9

What are the 6 principles of stability?

Answer 9

The lower the centre of gravity the more stable.
Line of gravity in the centre of base of support.
Widen base of support to increase stability.
Greater mass = Greater stability.
Greater friction = Greater stability.
Focusing on a still object increases stability.

Question 10

What is meant by limits of stability?

Answer 10

The maximum distance a person can intentionally displace their centre of gravity without loosing their balance when stepping or reaching for assistance.

Question 11

What are the 2 factors that keep us in an upright position?

Answer 11

Tilting Reactions.

Righting Reactions.

Question 12

What is meant by Tilting reactions?

Answer 12

Used to keep your body upright when on moving surface.

Question 13

What is meant by Righting reactions?

Answer 13

Used to keep the body upright when you move across a stable object.

Question 14

Define balance?

Answer 14

Balance is the ability to control equilibrium.

Question 15

What are the 2 balance categories?

Answer 15

Static Balance: Maintaining balance when holding a position.

Dynamic Balance: Maintaining balance while moving.

Question 16

Define Gravity?

Answer 16

The force by which all bodies are attracted to earth.

Question 17

What are the 3 characteristics of gravity?

Answer 17

Applied constantly.
Applied in one direction only.
Acts upon each mass particle of the body and other implements or objects.

Question 18

What is line of gravity?

Answer 18

An imaginary line that passes through the COG.