Module 1: An Introduction to Motion

Question 1

motion diagrams

Answer 1

the composite image shows an object’s positions at several equally spaced instants of time

Question 2

two step process for solving motion problems

Answer 2

• representation
• analyze with the language of mathematics

Question 3

motion

Answer 3

the change of an object’s position/orientation with time

Question 4

trajectory

Answer 4

the path along which an object moves

Question 5

4 basic types of motion `

Answer 5

• straight line motion
• circular motion
• projectile motion
• rotational motion

Question 6

a video camera takes images at a fixed rate. each separate image is called a…

Answer 6

frame

Question 7

motion diagram

Answer 7

the composite image shows an object’s positions at several equally spaced instants of time

Question 8

operational definitions

Answer 8

the concepts are defined in terms of a particular procedure or operation

Question 9

constant speed motion diagram

Answer 9

images that are equally spaced

Question 10

speeding up motion diagram

Answer 10

there is an increasing distance between the images

Question 11

slowing down motion diagram

Answer 11

there is a decreasing distance between the distance

Question 12

more complex motion diagrams show changes in…

Answer 12

speed and direction

Question 13

oscillating system

Answer 13

something that moves back and forth around an equilibrium position (examples: vibrating guitar string, sound wave, jiggling atoms in a crystal)

Question 14

modeling

Answer 14

stripping away the details to focus on essential features

Question 15

model

Answer 15

a highly simplified picture of reality, but still captures the essence of what we want to study

Question 16

descriptive models

Answer 16

what are the essential characteristics and properties of phenomenon? how do we describe it in the simplest possible terms?

Question 17

explanatory models

Answer 17

why do things happen as they do?
predictive power; allow us to test whether a model gives an adequate explanation of our observations

Question 18

t/f: the motion of the object as a whole is not influenced by the details of the object’s size and shape

Answer 18

true

Question 19

for the purpose of analyzing motion, we often consider the object as if it were just a…

Answer 19

single point

Question 20

particle

Answer 20

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

Question 21

simplifying a motion diagram using the particle model

Answer 21

Question 22

the particle model

Answer 22

allows us to see connections that are very important but that are obscured or lost by examining all the parts of an extended, real object

Question 23

t/f: all objects falling under the inlfuence of gravity move in a different manner if no other forces act

Answer 23

false; all objects falling under the influence of gravity move in exactly the same manner if no other forces act

Question 24

the particle model for two falling objectts

Answer 24

Question 25

one dimensional motion

Answer 25

the motion of an object that can move only along a straight line

Question 26

position

Answer 26

your location at a particulat instant in time

Question 27

origin

Answer 27

reference point from which all distances are to be measured

Question 28

describing your position

Answer 28

Question 29

in order to specify how far out object is from the origin, we lay down... along the line of the objects motion

Answer 29

an imaginary axis

Question 30

coordinate system

Answer 30

an origin and an axis marked in both the positive and negative directions can be used to unambiguously locate the position of an object

Question 31

the coordinate system used to describe objecys along a country road

Answer 31

Question 32

coordinate

Answer 32

the symbol that represents a position along an axis

Question 33

a coordinate system for a 50 meter race

Answer 33

Question 34

examples of one dimensionsal motion

Answer 34

Question 35

the motion diagram of a car that travels at constant speed and then brakes to a halt

Answer 35

Question 36

sam undergoes a displacement △x from position xi to position xf

Answer 36

Question 37

displacement

Answer 37

a change of position

Question 38

the change in any quantity is...

Answer 38

the final value of the quanity minus its inital value

Question 39

signed quantity

Answer 39

it can be wither positive or negative

Question 40

t/f: displacement is a signed quantity

Answer 40

true

Question 41

a displacement is a signed quantity. here △x is a negative number

Answer 41

Question 42

time intervals

Answer 42

changes in time

Question 43

the motion diagram of a bicycle moving to the right at a constant speed

Answer 43

Question 44

a time interval (△t) measures...

Answer 44

the elapsed time as an object moves from an initial position xi at time ti to a fianl position xf at time tf

Question 45

uniform motion

Answer 45

motion at a constant speed

Question 46

motion diagrams for a car and a bicycle

Answer 46

Question 47

t/f: the smaller the distance traveled by an object in a given time interval, the greater its speed

Answer 47

false; the greater the distance traveled by an object in a given time interval, the greater its speed

Question 48

speed of an object

Answer 48

speed = (distance traveled in a given time interval) / (time interval)

Question 49

two bicycles traveling at the same speed, but with different velocities

Answer 49

Question 50

velocity of a moving object

Answer 50

velocity = displacement / time interval = △x / △t

Question 51

speed vs. velocity

Answer 51

speed measures how fast an object moves; velocity measures an object's speed and direction

Question 52

instantaneous velocity

Answer 52

the velocity of an object at a particular instant in time

Question 53

per

Answer 53

associates the number of units in the numerator with one unit of the denominator