Lecture 15

Question 1

Human body moment of inertia about an axis is

Answer 1

Variable

Question 2

Humans can manipulate their

Answer 2

Momentum of inertia

Question 3

Manipulating moment of inertia in human body movement examples

Answer 3

Tucking in a dive

Bringing arms in on spinning in skating

Question 4

Linear momentum equation

Angular momentum equation

Answer 4

P = mv

L = moment of inertia x angular velocity

Question 5

Newtons 1st law of motion (angular motion)

Answer 5

An object at rest tends to remain at rest and an object that is spinning tends to spin with constant angular velocity

UNLESS it is acted on by a nonzero net TORQUE

Question 6

Conservation of angular momentum happens if

Answer 6

There is no net external torque act on the object

Question 7

What does newtons first law not require in angular motion

Answer 7

Angular velocity to be constant

Instead the product of moment of inertia x angular velocity must be constant

Question 8

When we extend our arms we cause

Answer 8

Angular momentum to remain constant

Moment of inertia to increase and angular velocity to decrease

Opposite for arms flexed

Question 9

Newtons 2nd law of motion in angular motion is when

Answer 9

sum of Torque cannot = 0

Question 10

Object will accelerate in

Answer 10

the direction of the net external torque

Question 11

The angular acceleration will be directly proportional to

Answer 11

The net external torque

Question 12

The angular acceleration will be inversely proportional to

Answer 12

The moment of inertia

Question 13

What is the equation for sum of torque

Answer 13

Sum of Torque = moment of inertia x angular acceleration