Chapter 2: Describing Motion: Kinematics in One Dimension

Question 1

What is mechanics?

Answer 1

The study of motion of objects and the related concepts of force and energy.

Question 2

What two parts is mechanics separated into?

Answer 2

Kinematics and Dynamics.

Question 3

What is Kinematics?

Answer 3

The description of how objects move.

Question 4

What is Dynamics?

Answer 4

Deals with force and why objects move as they do.

Question 5

What is transitional motion? (which is the kind of motion this chapter deals with).

Answer 5

Objects that move without rotating.

Question 6

In this chapter( and card set), what will we be concerned with the motion of?

Answer 6

Objects that move along a straight line path, also know as motion in one dimension.

Question 7

We will often use the concept or model of an idealized particle which is what?

Answer 7

Considered to be a mathematical point with no spatial extent (no size).

Question 8

A point partial can only undergo what type of motion?

Answer 8

Translation motion.

Question 9

The particle model is useful when?

Answer 9

We are interested in translational motion only.

Question 10

REFERANCE FRAMES AND DISPLACEMENT

Answer 10

REFERANCE FRAMES AND DISPLACEMENT

Question 11

What is a reference frame or a frame of reference used for?

Answer 11

Any measurement of position, distance, or speed must be made in respect to a frame of reference.

Question 12

While you are on a train traveling at 80 km/h, suppose a person walks to the front of a train at 5 km/h. What is his frame of reference?

Answer 12

This 5 km/h is the persons speed with respect to the train as a frame of reference.

Question 13

With respect to the ground how fast is that person moving on that train?

Answer 13

80 km/h +5 km/h = 85 km/h.

Question 14

When stating speed what is it always important to state

Answer 14

It is always important to specify the frame of reference.

Question 15

Why do we have a reference frame really?

Answer 15

To avid confusion.

Question 16

When specifying the motion of an object it is important to specify not only the speed but also what?

Answer 16

The direction of motion.

Question 17

Often in physics how do we specify a direction?

Answer 17

Using north, east, south, and west, and by up and down.

Question 18

In physics what do we usually draw as a frame of reference?

Answer 18

A coordinate system.

Question 19

What do we place at the origin of the coordinate system?

Answer 19

0

Question 20

In three dimensions what other axis is added to the coordinate system?

Answer 20

z.

Question 21

What is displacement?

Answer 21

The change in position of an object; how far and object is from the starting point.

Question 22

What are vectors?

Answer 22

Quantities that have both magnitude and direction.

Question 23

To see the difference between displacement and distance imagine a person walking 70m to the east and then turning around and walking back west 30m, what is the distance the person traveled and what is the displacement?

Answer 23

The total distance traveled is 100 m, but the displacement is now only 40 m since the person is now only 40 meters from the starting point.

Question 24

What are some examples of vector quantities?

Answer 24

Displacement,

Question 25

What are vectors represented by in diagrams?

Answer 25

Arrows.

Question 26

When will we deal with vectors more?

Answer 26

In chapter 3.

Question 27

In one dimension motion; vectors that point in the opposite direction will do what?

Answer 27

Have a negative sign on the magnitude quantity.

Question 28

SKILL 1: CALCULATING AVERAGE VELOCITY

Answer 28

Question 29

What does the greek symbol delta (triangle) stand for?

Answer 29

A change in.

Question 30

What does delta(x) mean?

Answer 30

A change in X. Or a change in position which is displacment.

Question 32

What does the "change in" any quantity mean?

Answer 32

The final value of that quantity minus the original of that quantity.

Question 33

Whats the equation for displacment?

Answer 33

Delta(x) = x(2) - x(1) is change in position which is displacment.

Question 34

AVERAGE VELOCITY

Answer 34

AVERAGE VELOCITY

Question 35

What is an importnat aspects of a moving object?

Answer 35

How fast an objcet is moving - its speed and velocity.

Question 36

What does the term speed refer to?

Answer 36

How far an object travels in a given time interval, reguardeless of direction.

Question 37

What is the definition of average speed?

Answer 37

The total distance travled along its path divided by the time it takes to travel this distance.

Question 38

Whats the equation for average speed?

Answer 38

Distance traveled/time elapsed.

Question 39

In physics does speed and velocity mean the same thing? Why?

Answer 39

No; **Speed** is just a positive number with a unit. **Velocity** is used to signify both the magnitude (numerical value) of how fast an object is moving and also the direction in which it is moving.

Question 40

Is velocity a scalar or a vector?

Answer 40

It has both magnitude and direction so it is a vector.

Question 41

What is the second diffrence between speed and velocity?

Answer 41

The average velocity is defned in terms of displacemnt rather than total distance traveled.

Question 42

When motion is in one dimension what does average speed and average velocity have in common?

Answer 42

They have the same magnitude, but in other cases may differ.