Lecture 12 - Inertia and Momentum

Question 1

What does inertia depend on?

Answer 1

Mass and velocity

Question 2

What is momentum?

Answer 2

A resistance to change in velocity of a moving body

Question 3

What is the equation for linear momentum?

Answer 3

L = mv

Question 4

Can linear momentum be negative?

Answer 4

Yes

Question 5

The sign of momentum is always the same as the sign of ______.

Answer 5

Velocity

Question 6

What were two reasons that test subjects failed a sit to stand test conducted during a study in applied biomechanics?

Answer 6

Sitback and step

Question 7

What is sitback?

Answer 7

When subjects were unable to generate the momentum they needed to stand up

Question 8

What is step

Answer 8

When subjects were unable to control the direction of the momentum of they did generate

Question 9

Is inertia the same at different speeds?

Answer 9

No

Question 10

What is moment of inertia?

Answer 10

The angular equivalent to mass

Question 11

How is can the moment of inertia be altered?

Answer 11

By the distribution of mass relative relative to the axis of rotation

Question 12

What is the simple equation for moment of inertia?

Answer 12

I = mp2

Question 13

What is the complex equation for moment of inertia?

Answer 13

I = sum(mp2)

Question 14

What is p represent in the moment of inertia equation?

Answer 14

The distance from the center of mass to the axis of rotation

Question 15

How can you increase the moment of inertia?

Answer 15

By increasing the mass or distance from the axis of rotation

Question 16

Which variable has a larger effect on the moment of inertia?

Answer 16

The distance from the axis

Question 17

What is the center of mass?

Answer 17

A fictitious point where all the mass is considered to be concentrated

Question 18

Where is the center of mass located in a body that is symmetrical and has uniform density?

Answer 18

At the geometric center

Question 19

What is Newton’s first law?

Answer 19

A body will remain at rest or continue to move with a constant speed in a straight line unless acted upon by an outside force

Question 20

What is force?

Answer 20

A push or pull by one body on another

Question 21

What is propulsive force?

Answer 21

A force that is causing a body to speed up

Question 22

What is breaking force?

Answer 22

A force that is causing a body to slow down