Chapter 2 Textbook

Question 1

What is the significance of motion diagrams?

Answer 1

They allow us to provide a simplified view of a motion of an object.

Question 2

_____ is essential to life.

Answer 2

Movement

Question 3

Define Motion

Answer 3

The change of an object’s position w time.

Question 4

What are the 4 basic types of motion?

Answer 4

Linear-Circular-Projectile-Rotational. LC-PR

Question 5

Define Translational Motion. Which of the 4 basic types of motion are included?

Answer 5

Motion in which the object moves through space. (Includes linear, circular, and projectile motion).

Question 6

Define Trajectory

Answer 6

The path along which an object moves.

Question 7

What does a motion diagram specifically show?

Answer 7

It shows an objects position at several, equally spaced instants of time.

Question 8

While using a camera to make a motion diagram, what is something essential to do?

Answer 8

Make sure that the camera is stationary and that you don’t “pan” it to track the moving object.

Question 9

In motion diagrams with images that are equally spaced, what is being shown?

Answer 9

The object is moving at a constant speed.

Question 10

In motion diagrams with an increasing distance between the images, what can be said of the speed of the object?

Answer 10

It is speeding up.

Question 11

In motion diagrams with a decreasing distance between the images, what can be said of the speed of the object?

Answer 11

It is slowing down.

Question 12

Define Particle

Answer 12

An object that can be represented as a mass at a single point in space.

Question 13

What are some distinguishing characteristics of particles?

Answer 13

They do not have a size, shape, top, or bottom .

Question 14

What does the Particle model of motion allow us to do?

Answer 14

It allows us to treat a moving object as if all of its mass was concentrated at a single point.

Question 15

When given two images with a differing number of particle locations captured, how could you tell which is going faster?

Answer 15

You must look at the distance between the particle points. The longer the distance, the faster it is going.

Question 16

What are the 2 most important facts about a moving object?

Answer 16

Where the object is and what time the object is in that position (Time and Position)

Question 17

How can position measurements be made?

Answer 17

By laying a coordinate system grid over a motion diagram.

Question 18

With respect to time, when you put t=0 seconds, what does that entail?

Answer 18

This is the instant you decide to start your clock or stopwatch, so it is the origin of your time coordinate.

Question 19

Negative numbers are not to be avoided. In a grid, what do they signify?

Answer 19

They simply locate an event in space or time relative to an origin.

Question 20

Define Displacement

Answer 20

The change of motion

Question 21

What is the formula for calculating displacement?

Answer 21

Final Position - Initial Position

Question 22

What is the significance of a displacement vector? What is the symbol for it?

Answer 22

We use it by drawing an arrow between the dots of the motion diagram.

DELTA r with a little arrow on top of the “r”.

Question 23

Define Scalar

Answer 23

A single number with a unit that describes a physical quantity. This value can be negative, 0, or positive.

Question 24

Define Vector

Answer 24

A quantity having both a size and a direction.

Question 25

Define Magnitude

Answer 25

The size or length of a vector.

Question 26

How do you indicate a vector in writing?

Answer 26

By having an arrow over the letter.

Question 27

Can the value of a magnitude be negative?

Answer 27

NEVER; it’s always positive.

Question 28

What is the 1st step in analyzing a motion diagram?

Answer 28

Determine all of the displacement vectors.

Question 29

Based on displacement vectors, how can we determine if something is speeding up or slowing down?

Answer 29

If the displacement vectors are increasing in length, it is speeding up. If they are decreasing in length, they are slowing down.

Question 30

What does the time interval represent?

Answer 30

It represents the elapsed time it takes for an object to move from one position to the next.

Question 31

Is the value DELTA T (time interval) independent or dependent with respect to the specific clock used to measure the times?

Answer 31

Independent.

Question 32

What is the formula for speed?

Answer 32

Speed (v)= Distance Traveled/ Time Interval Spent Traveling= d/ Delta T

Question 33

What is the formula for Velocity?

Answer 33

Velocity (v w/ an arrow on top) =displacement/ time interval= Delta R (arrow)/Delta T

Question 34

How do an object’s velocity vector and displacement vector behave with respect to one another?

Answer 34

They point in the same direction, the direction of motion.

Question 35

Verbally speaking, how can we think of speed and velocity?

Answer 35

Speed can be thought of as “How Fast?” And velocity can be thought of as “How fast and in what direction?”

Question 36

What does the length of a velocity vector represent?

Answer 36

The average speed with which the object moves between the 2 points. The longer, the faster.

Question 37

What is the ratio of DELTA R/Delta T called?

Answer 37

Rate of change of position

Question 38

What is the ratio of Delta V/Detla R called?

Answer 38

The rate of change of velocity.

Question 39

What is the formula for acceleration?

Answer 39

Acceleration (“a” with an arrow)= velocity change/ time interval= Delta V (w/ arrow)/Delta T

Question 40

How does the acceleration vector point with respect to the velocity vector?

Answer 40

It points in the same direction.

Question 41

What is something to remember regarding vector addition problems?

Answer 41

Delta V= Vb-Va ; so, Va+Delta V= Vb

Question 42

What are the steps to finding the acceleration vector?

Answer 42

Draw the two vectors. Delta V is going to be the distance between Vb-Va. If Vb is shorter than Va, then the velocity vector will point in the opposite direction. Then, with both vectors back to back and a dot separating them, you draw the acceleration vector in the middle of that dot.

Question 43

Does the length of the acceleration vector have to be the same as the velocity vector?

Answer 43

No, it just mainly needs to be pointing in the same direction.

Question 44

What is the rule for velocity vectors and the number of dots?

Answer 44

For every 2 dots, there is one velocity vector.

Question 45

What has to be true for V and A for an object to be speeding up?

Answer 45

They have to point in the same direction.

Question 46

What has to be true for V and A if an object is slowing down?

Answer 46

V and A must point in opposite directions.

Question 47

When is an object’s velocity constant?

Answer 47

Only when a (w/ an arrow)=0

Question 48

Does acceleration in physics always entail that something is speeding up?

Answer 48

No, acceleration refers to changing the velocity, no matter what the change is.

Question 49

What does zero acceleration mean for velocity?

Answer 49

If the acceleration is 0, there is no velocity.

Question 50

What are the 3 fundamental quantities that motion can be described with?

Answer 50

Position-Velocity-Acceleration

Question 51

How can motion along a straight line be described?

Answer 51

It can only be “forward” or “backward”

Question 52

What are the 2 essential features of a coordinate axis?

Answer 52

1. An origin to define zero 2. An x or y label (w/ units) at the positive end of the axis .

Question 53

Where are the positive ends of the x and y axis located respectively?

Answer 53

To the right for X and up for Y

Question 54

What does the sign of acceleration tell us?

Answer 54

Which way the vector points, not whether the object is speeding up or slowing down.

Question 55

What is meant when we say a graph of “a versus b”?

Answer 55

It menas that A is graphed on the vertical axis and B is graphed on the horizontal axis.

Question 56

Define Position Graph

Answer 56

A continuous line or curve that shows an object’s position as a function of time.

Question 57

What are the 4 representations of knowledge in physics?

Answer 57

Verbal-Pictorial-Graphical-Mathematical VP-GM

Question 58

What is the rule regarding whole numbers and significant figures?

Answer 58

Whole #s have at least 2 significant figures.