51 terms

# Science Ch 9 review

#### Terms in this set (...)

What does the straight line show on the acceleration graph?
Constant speed
What does the acceleration graph show?
Speed vs time
Can an object be accelerating even if it's speed is constant?
Yes
Means an object is not moving
Horizontal (flat line)
Where is time on a graph?
X axis (horizontal)
Where is distance on a graph?
Y axis (vertical)
Describes both speed and direction of an object's motion
Velocity
Ratio of 2 measurements
Rate
Distance an object travels per unit of time
Speed
Used to determine motion
Referenece point
When is an object in motion
When its distance from another object is changing.
What is a reference point?
a place or object used for comparison to determine if something is in motion.
An object is in motion if it changes position relative to what
a reference point
What is the whole name of SI
International Systems of Unit
what number is the SI based on?
10
What is the basic unit of length
meter
How many centimeters are there in a meter
100
how many meters are there in a kilometer
1000
what is the formula used to calculate the speed of an object?
Speed = distance / time
How would you find the average speed of a cyclist throughout the entire race
Total distance/ total time
Speed in a given direction is called
velocity
If a storm is approaching moving at 15 km/h. what do you need to know to determine its velocity?
the direction it is moving.
what is the steepness or slant of a line on a graph called
slop
what is the formula used to find the slope of a line
slope = rise / run
what is acceleration
the rate at which velocity changes
acceleration involves a change in what two components?
speed and direction
any time the speed of an object increase, the object experiences what
acceleration
What are the three things that acceleration refers to
1. increasing speed
2. decreasing speed
3. changing direction
What is deceleration another word for
negative acceleration
can an object be accelerating even if its speed is constant
yes
what is an example of acceleration
car follows a gentle curve in the road
a batter wings a bat to hit a ball
a runner slows down after finishing a race
when the moon revolves around earth at a fairly constant speed. Is the moon accelerating?
the moon is accelerating because it is constantly changing direction as it revolves around earth.
increasing speed is the same as what
speeding up
decreasing speed is the same as what
slowing down
changing direction is the same as what
turning
what must you calculate to determine the acceleration of an object?
change in velocity during each unit of time
what is the formula used to determine acceleration?
final velocity - initial velocity / time
what is true about calculating the acceleration of a moving object
if an object is moving without changing direction, then its acceleration is the change in its speed during one unit of time.
If an objects' speed changes by the same amount during each unit of time, then the acceleration of the object at any time is the same.
If an object's acceleration varies, then you can describe only average acceleration.
If velocity is measured in kilometers/hour and time is measured in hours what is the unit of acceleration
km/h2
If a graph of distance versus time is a straight line the graph shows what type of relationship
linear
if a graph of distance versus time is a curved line the graph shows what type of relationship
nonlinear
If the graph line is slanted and straight what does the line show about the acceleration of the object?
Accleration is constant
what happens when an object's distance from another is changing
motion
what is a place or an object used for comparison to determine if something is in motion
reference point
what is the system of measurement scientists use to communicate information clearly
SI - Internaitonal System of Units
what is the basic SI unit of lenght
meter
what is the distance an object travels in one unit of time
speed
what is speed in a given direction
velocity
the steepness, or slant of a line on a graph
slope
the major pieces of earth's crust
plates
what is the rate at which velocity changes
acceleration.