L21;C14

Question 1

We treat the body as as ______ ______ _____ while dealing with angular kinetics

Answer 1

One rigid object

Question 2

We must look at ______ and ______ in order to settle equilibrium

Answer 2

Forces, torques

Question 3

First law of inertia (Newton’s) with respect to angular kinetics

Answer 3

Objects will remain in current states unless acted upon by external torques. ΣT=0

Question 4

Explain the second law of acceleration for angular kinetics

Answer 4

An applied net torque causes an object to accelerate directly proportional to the torque magnitude in the same direction of force.

ΣT=Ia

Question 5

Explain the third late of reaction in angular kinetics.

Answer 5

Every applied torque has an equal or opposite reaction torque.

T action= T reaction

Question 6

______ forces, which can be considered off centre, may cause rotation and translation

Answer 6

Eccentric

Question 7

____ forces can only produce translation

Answer 7

Centric

Question 8

True or false: individual forces may have potential to produce rotation

Answer 8

True

Question 9

____ is a measure of inertia of an object

Answer 9

Mass

Question 10

Heavier object, means _______ to change state of motion

Answer 10

Harder

Question 11

In angular terms, heavier an object means harder to ______ ______ which evidently determines how mass is distributed in an object

Answer 11

Change motion

Question 12

In linear kinetics: inertia is directly proportional to _____ _____

In angular kinetics: inertia is directly proportional to ______ AND _________

Answer 12

objects mass

Mass, distribution

Question 13

What is angular inertia?

Answer 13

The mass moment inertia is the inertial property for angular motion and is calculated by summing particles masses and distance to axis of rotation

Question 14

What is the formula for the mass moment of inertia?

Answer 14

I=mk^2

Question 15

In most objects, what happens to mass? Does it differ with respect to its mass moment of inertia?

Answer 15

In most objects, mass doesn’t change. But MMI will change depending on AoR

Question 16

What is k? What does it represent?

Answer 16

K represents the radius of gyration, this is used to represent an objects mass distribution with respect to given object

Question 17

When is K smallest?

Answer 17

When rotating around its own axis

Question 18

How can changing the shape influence the mass?

Answer 18

Changing the shape influences how mass is distributed around an axis of rotation

Question 19

What are the three axi of rotation?

Answer 19

Anteroposterior, medilateral, longitudinal

Question 20

Momenta are _______ that possess both ______ and _______

Answer 20

Vectors, magnitude, direction

Question 21

Angular momentum of single segments with respect to AoR consists of TWO main components:

Answer 21

1. Local term- segments angular momentum about its own CG

2. Remote term- segments angular momentum about whole body CG

Question 22

During a whole body action such as a dive, momentum is conserved meaning I and w change. How and why do they?

Answer 22

As you tuck in from the dive, your ‘I’ begins to decrease due to the K value decreasing. K value decrease due to the CoM coming closer to the AoR on the body.

Question 23

What is the formula for angular impulse? What can you derive it to?

Answer 23

T•∆t= F•dt•∆t

Question 24

Is angular impulse a vector or scaler?

Answer 24

It is a vector since its magnitude and direction are specified

Question 25

Another world for radial acceleration is _________ accerlation

Answer 25

Centripetal

Question 26

What does centripetal acceleration result from?

Answer 26

A change in direction of the transverse component of the point of velocity

Question 27

Since a point is accelerating towards the centre, what kind of force must be involved?

Answer 27

A centre seeking force

Question 28

Any force that causes an object to exhibit circular motion is referred to as _______ ________

Answer 28

Centripetal force

Question 29

Explain the concept of inertia again with respect to kinetics? (Use accerlation in answer)

Answer 29

It is the tendency to resist acceleration, a bodies inertia is directly proportional to its mass

Question 30

More mass closer to axis of rotation ________ to rotate the object

Answer 30

Easier

Question 31

What are the three factors that effect the magnitude of the bodies of angular momentum?

Answer 31

1. Mass
2. Distribution of mass
3. Angular velocity

Question 32

What has the greatest effect on angular momentum?

Answer 32

Distribution of mass

Question 33

What happens to angular momentum in the absence of torques?

Answer 33

It is constant

Question 34

What is the most influential factor for rotation?

Answer 34

Speed