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Flashcards in Motion and Forces Deck (51)
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1
Q

what is a place or object used for comparison to determine if something is in motion?

A

reference point

2
Q

how do you know if an object is in motion?

A

If it changes position relative to a reference point.

3
Q

in science, what system is used to measure distance, mass, volume?

A

International System of Units (metric)

4
Q

the standard unit to measure distance

A

meter

5
Q

1,000 meters

A

kilometer

6
Q

1/100th of a meter

A

centimeter

7
Q

how many millimeters make a centimeter?

A

10

8
Q

what is the term for the distance an object travels per unit of time?

A

speed

9
Q

what is the formula for speed?

A

S=D/T

10
Q

how to you determine average speed?

A

divide the total distance traveled by the total time traveled

11
Q

what is the term for speed in a given direction?

A

velocity

12
Q

to graph motion, how would the axes be labeled?

A

time on the x axis and distance on the y axis

13
Q

on a graph, what tells you how fast distance changes in relation to time?

A

the slope

14
Q

on a distance-versus-time graph, what does a steep slope tell you about the speed of the object?

A

the steeper the slope, the faster the speed

15
Q

on a time distance graph, what does a flat line indicate about the speed?

A

the speed is zero

16
Q

what is the term for the rate at which velocity changes?

A

acceleration

17
Q

how can you tell if an object is accelerating?

A

if it changes speed, changes direction or decreases the speed

18
Q

speeding up means

A

accelerating

19
Q

if you calculate the change in speed per unit of time, you are measuring…

A

acceleration

20
Q

what SI units are used for acceleration?

A

m/s/s or m/s2

21
Q

what is the formula for acceleration?

A

A=final speed - initial speed/ time

22
Q

if the final speed is 60m/s and the initial speed is 0m/s and the time of travel is 10 s, what is the acceleration?

A

6 m/s/s or 6 m/s2

23
Q

on an acceleration graph does a flat line mean the object is not moving?

A

No, it just means that it is not accelerating…the speed is constant.

24
Q

what does a curved line on a distance vs. time graph indicate?

A

the object is accelerating

25
Q

a push or a pull

A

a force

26
Q

what 2 factors describe a force?

A

strength and direction

27
Q

what units measure force?

A

newtons

28
Q

on a graph, how are the strength and direction of a force shown?

A

by vectors

29
Q

the combination of all forces acting on an object is called

A

net force

30
Q

when forces are pushing or pulling in the direction, they are combined forces and what math function would you use to determine the net force?

A

addition

31
Q

when forces are pushing or pulling in an opposite direction, they cancel one another out to some degree. what math function would you use to determine the net force?

A

subtraction

32
Q

if opposing forces are of equal strength, is there any motion?

A

nope…they are balanced

33
Q

which forces can cause an object to start moving, stop moving, or change direction?

A

unbalanced

34
Q

equal forces acting on one object in opposite directions are called

A

balanced forces

35
Q

the force that two surfaces exert on each other when they rub against each other is called

A

friction

36
Q

what determine the force of friction?

A

how hard the surfaces push together and the types of surfaces involved

37
Q

which would produce more friction, sandpaper or water?

A

sandpaper

38
Q

why are roads scattered with sand in winter time?

A

to improve friction and provide traction

39
Q

in which direction does friction work compared to motion?

A

the opposite direction

40
Q

friction that acts on objects that are not moving is called

A

static

41
Q

type of friction that occurs when two solid surfaces slide over each other

A

sliding friction

42
Q

type of friction of marbles rolling across a floor

A

rolling friction

43
Q

slipping on a banana peel type of friction

A

sliding

44
Q

riding a bike down a hill type of friction

A

rolling and fluid

45
Q

type of friction swimming in a pool

A

fluid friction

46
Q

the force that pulls objects toward each other

A

gravity

47
Q

law that states that the force of gravity acts between all objects in the universe

A

law of universal gravitation

48
Q

does gravity act everywhere in the universe?

A

yep…everywhere that there is mass

49
Q

what two factors affect the gravitational attraction between objects?

A

mass and distance

50
Q

which exerts a greater gravitational attraction…an elephant or a mouse (given equal distances)

A

an elephant because it has greater mass

51
Q

which exerts a greater gravitational attraction …a mouse in the next room or an elephant across the universe?

A

the mouse because it is so much closer