EXSC 350 Chap 7

Question 0

Moment of Inertia

Answer 0

Resistance to angular acceleration.

Depends on mass of body and distribution of mass relative to axis of rotation/COG

Question 1

Whole body Inertia (I) =

Answer 1

Sum of m(r)^2

Units: Kgm^2

Radius (distance to the COG)
Inertia pertaining to the WHOLE body

Question 2

Body segment Inertia =

Answer 2

m(k)^2

Units: Kgm^2
k = radius of gyration (d from axis to center)

Question 3

Body segment Inertia of lower value is ______ to cause rotation.

Answer 3

Easier

Question 4

Body segment Inertia of higher value is ______ to cause rotation.

Answer 4

Harder

Question 5

Centripetal Force (Fc) =

Answer 5

m(r)(w)^2

w = angular velocity (rad/sec)

Question 6

Centripetal Force ( Fc) definition

Answer 6

A force that prevents rotating body from leaving its circular path, while fixed around an axis.

Fc is always in the direction of center of rotation

Question 7

Centrifugal Force (Fc) = 
And definition

Answer 7

m(r)(w)^2

w = angular velocity (rad/sec)

A force of equal magnitude and opposite in direction created as a reaction to the centripetal force.
(Like Newton’s 3rd Law)

Question 8

Angular Momentum (H) =

Answer 8

I(w)

I = moment of inertia 
w = angular velocity (rad/sec)

Also:
H = mk^2w
k - radius of gyration

Question 9

Angular momentum (H) is conserved when _______ is the only acting external force

Answer 9

Gravity

Question 10

Angular Momentum (H) remains constant in the absence of _______ _______

Answer 10

External torques

Question 11

H (+)

Answer 11

Counterclockwise

Question 12

H (-)

Answer 12

Clockwise

Question 13

Momentum can be transferred from _______ to _______

Answer 13

Angular to Linear

Question 14

Sports that involve angular momentum (H)

Answer 14

Diving, gymnastics, figure skating

Question 15

Angular Impulse (Tt) = 
And definition

Answer 15

(Iw)2-(Iw)
Or
Fperendicular(d)t = (mk^2w)2-(mk^2w)1

Angular impulse is and angular force (torque) acting over some time duration.

Question 16

Linear Kinetic Quantities

Answer 16

Mass (m)
Force (F)
Momentum (M)
Impulse (I)

Question 17

Angular Kinetic Qualities

Answer 17

Moment of Inertia (I)
Torque (T)
Angular Momentum (H)
Angular Impulse (Tt)

Question 18

Newton’s 1st Law (angular motion)

Answer 18

A rotating body will maintain constant angular motion unless acted on by an external torque (T)

Question 19

Newton’s 2nd Law (angular motion)

Answer 19

External T produces angular acceleration of a body that is directly proportional to the magnitude of the T in the same direction of the T and inversely proportional to the body’s moment of Inertia.

Question 20

Newton’s 3rd Law (angular motion)

Answer 20

For every T exerted by one body on another, there is an = and opposite T exerted by the second body on the first

Ex: Centripetal/centrifugal forces