Understanding Science, Scientific Tools, Speed and Velocity, Position and Motion, and Acceleration Flashcards
Is the process of changing position.
Motion
Is the difference between the initial position and the final position of an object.
Displacement
Is the path taken
Distance
What does a description of a location include?
It usually states the location realitive to a certain point.
What does a COMPLETE description of your position include?
Distance, a direction, and a reference point.
The description of an object’s position depends on the what?
It depends on the reference point.
The reference direction is a what direction?
It is a positive direction.
The opposite direction is a what direction?
It is a negative direction.
What’s the definition of a reference point?
Is a starting point that can be used to locate place or thing.
When you are using two directions, you are using two whats?
You are using two dimensions.
To find a position in two dimensions you must do what?
Choose a reference point
Specify reference directions
Determine the distance along each reference direction
When can displacement and direction be equal.
It can only be equal if the motion is in one direction.
True or false?
Displacement is the distance an object moves along a path.
False. Displacement is the distance and direction of an object from its starting point.
True or False?
The description of an object’s position depends on the reference point.
True. Position is described by how far an object is from a reference point.
How did the description of your movement depend on the point at which you started?
The distance and the direction to a location can change if the reference point changes.
How does the description of an object’s position depend on a reference point?
An object’s position is its distance in a certain direction from a reference point.
Why is a reference point useful in describing positions of an object?
The reference point provides a starting from which all distances can be measured and compared.
How can you describe the position of an object in two dimensions?
It can be described by choosing a reference point and two reference directions then starting the distance along each reference direction.
What is the difference between distance and displacement?
Distance is the path taken. However, displacement is the difference between the initial position and the final position of an object.
The difference between the initial position and the final position of an object is its __________.
Displacement
Explain why a description of position depends on a reference point.
Position is the distance and direction f an object of a reference point. If the reference point changes, the distance and direction of the object from the reference point may change.
To describe a position in more than one dimension, you must use more than one: A. displacement. B. reference direction. C. reference point. D. type of motion.
B- reference direction
If you walk 2 km from your house to a store and then back home, what is your displacement?
The displacement is 0 km.
An airplane rolls down the runway. Compared to which reference point is the airplane in motion? A. the cargo the plane carries B. the control tower C. the pilot flying the plane D. the plane’s wing
B- control tower
Which describes motion in two dimensions? A. a car driving through a city B. a rock dropping off a cliff C. a sprinter on a 100-m track D. a train on a straight track
A- a car driving through a city
Which describes the greatest displacement?
A. walking 3 m east, then 3 m north, then 3 m west
B. walking 3 m east, then 3 m south, then 3 m east
C. walking 3 m north, then 3 m south, then 3 m north
D. walking 3 m north, then 3 m west, then 3 m south
B- walking 3 m east, then 3 m south, then 3 m east
Position relies on what three things?
Reference point, reference direction, and distance
Which pair of reference directions could be useful in describing a position in two dimensions and why? A. up and down B. left and right C. east and west D. west and north
D- west and north// because it can describe position in two dimensions
When is the displacement of an object the same as the distance that the object moves and why?
A. when the object moves in one direction only
B. when the object moves and then ends where it started
C. when the object moves halfway around a circle
D. when the object moves equal amounts in two directions
A- when the object moves in one direction only// displacement is the same as direction the motion is in one direction only.
It is a measure of the distance and object travels in a unit of time.
Speed
Is the rate of change of position in which the same distance is each second.
Constant speed
It is speed at a specific instant in time.
Instantaneous speed
It is the total distance traveled divided by the total time taken to travel that distance.
Average speed
It is the speed no direction of a moving object.
Velocity
When a car’s speed changes it moves a different what?
It moves a different distance each period of time.
Graphs that shows comparisons between distance and time are called what?
They are called distance-time graphs.
Constant speed is shown what on a distance-time graph.
It is shown as a straight line
You can use distance-time graphs to compare what?
The motion of two different objects.
On a graph the steeper the line indicates what?
It indicates a faster speed
You an use distance-time graphs to calculate the what?
The average speed of an object.
If the speed of an object changes instead of being constant, it’s motion on a distance-time graph is seen as what type of line?
It is seen as a curved line
It something is not constant you can calculate its average speed by what?
By choosing a starting point and an ending point.
The velocity of an object can be represented by what?
It can be represented by an arrow.
On a graph a greater speed is shown by a what?
It is shown by a longer line.
The arrow points in the objects what?
It points in the objects movement.
List the three ways velocity changes
When the speed of an object changes
The direction that the object moves changes
When both the speed and direction change
Example is a basketball.
Why does the velocity continually change?
It changes because both the speed and direction change as the ball bounces.
How do you calculate speed?
By dividing the distance traveled, by the time it takes to go that distance.
What is the SI unit for speed?
It is m/s.
The symbol v(with a line over it) represents what term?
It represents average velocity.
Average speed (in m/s)=?
Total distance (in meters) –––––––––––––––––––––– Total time (in seconds)
[v=D/t]
What are the steps to average speed
- Choose one point on the line (graph)
- Choose another point on the line
- Find the time
- Find the distance
- Divide the difference in distance, by the difference in time
True or False?
Constant speed is the same as average speed.
False. Speed that does not change over time is constant speed. Average speed is the total distance traveled divided by the total time taken to travel that distance.
True or False?
Velocity is another name for speed.
False. Velocity includes both speed and direction.
How would the distance the car travels each second change if it were slowing down?
The distance would decrease.
It takes Ahmed 50 s on his bicycle to reach his friend’s house 250 m away. What is his average speed?
5 m/s.
A truck driver makes a trip that covers 2,380 km in 28 hours. What is the driver’s average speed?
85 km/h.
Distinguish between speed and velocity.
Speed is the distance something travels divided by the time elapsed. Velocity includes both the speed and the direction of motion.
How can you calculate average speed from a distance-time graph?
Average speed is the total distance traveled during a time interval
Describe three ways a bicyclist can change velocity.
They can speed up, slow down, or change direction
Which choice is a unit of speed? A. h/mi B. km/h C. m2/s D. N·m2
B- km/h
Which has the greatest average speed? A. a boat sailing 80 km in 2 hours B. a car driving 90 km in 3 hours C. a train traveling 120 km in 3 hours D. a truck moving 50 km in 1 hour
D- a truck moving 50 km in 1 hour
Which have the same velocity?
A. a boy walking east at 2 km/h and a man walking east at 4 km/h
B. a car standing still and a truck driving in a circle at 4 km/h
C. a dog walking west at 3 km/h and a cat walking west at 3 km/h
D. a girl walking west at 3 km/h and a boy walking south at 3 km/h
C- a dog walking west at 3 km/h and a cat walking west at 3 km/h
Decide Aaron leaves one city at noon. He has to be at another city 186 km away at 3:00 M. The speed limit the entire way is 65 km/h. Can he arrive at the second city on time? Explain.
Yes. To arrive on time, his average must be 186 km divided by 3 hours, or 62 km/h, which is lower than the speed limit.
Describe a theme-park ride that has constant speed but changing velocity.
The ride slowing down
A train traveled 350 km in 2.5 h. What was the average speed of the train?
140 km/h
Is a measure of the change in velocity during a period of time.
Acceleration
And object accelerates when velocity changes, how though?
- Increasing speed
- Decreasing speed
- Changing direction
How is acceleration represented?
Because it has a direction it can be represented by an arrow.
Describe positive acceleration
It is speeding up in the forward direction.
Describe negative acceleration.
It is slowing down in the forward direction as well as speeding up in the reverse direction.
A speed-time graph shows what?
It shows how speed changes over time.
Describe an object at rest.
It is not moving, so the speed is zero
Describe a moving object
If a moving object is at a constant speed on a graph it is seen as a horizontal line.
Describe an object speeding.
The line is shaped an upward slope on a graph.
Describe an object slowing down.
It is downward slope on a graph
Mathematically how do you get acceleration?
Time interval divided by the time interval during the which the velocity changes.
Acceleration (in m/s^2)=
Final speed (in m/s) -initial speed (m/s)
––––––––––––––––––––––––––––––––––
Total time (in s)
a= F.S.-I.S.
–––––––
Time (s)
A speed-time graph is a horizontal line with a y-value of 4. Which describes the object’s motion? A. at rest B. constant speed C. slowing down D. speeding up
B. constant speed
Which describes motion in which the person or object is accelerating?
A. A bird flies straight from a tree to the ground without changing speed.
B. A dog walks at a constant speed along a straight sidewalk.
C. A girl runs along a straight path the same distance each second.
D. A truck moves around a curve without changing speed.
D. A truck moves around a curve without changing speed.
Which is a unit of acceleration? A. kg/m B. kg·m/s2 C. m/s D. m/s2
D. m/s2
After 2.0 s, Isabela was riding her bicycle at 3.0 m/s on a straight path. After 5.0 s, she was moving at 5.4 m/s. What was her acceleration?
.8 m/s2
The speed of a car traveling on a straight road increases from 63 m/s to 75 m/s in 4.2 s. What is the car’s acceleration?
2.9 m/s2
Is an objects distance in a certain direction from a reference point.
Position
The investigation and exploration of natural events and of the new information that results from those investigations.
Science
A process that uses a variety of skills and tools to answer questions or to test ideas.
Scientific Inquiry
The results of using one or more of your senses to gather information and taking note of what occurs.
Observations
A logical explanation of an observation that is drawn from prior knowledge or experience
Inference
A possible explanation for an observation that can be tested by scientific investigations.
Hypothesis
A statement of what will happen in the next sequence of events
Prediction
What comes after “Ask Questions”
Hypothesize and Predict
What connects with “Hypothesize and Predict”
Modify/Revise Hypothesis
What’s the next step after “Revise/Predict Hypothesis
Test Hypothesis
Test Hypothesis:
- Design an experiment
- Make a model
- Gather and evaluate evidence or research
- Collect data/record observations
What’s next after “Test Hypothesis”
Analyze results
Analyze Results:
- Graph Results
- Classify information
- Collect data/record observations
What comes after “Analyze Results”
Draw Conclusions
Draw Conclusions:
- Infer
* Reasoning
What is below “Draw Conclusions”
Hypothesis not supported
What is above “Draw Conclusions”
Hypothesis supported
What information is added to “Hypothesis Supported”
Repeat several times to confirm
What is next in the Scientific Inquiry after “Draw Conclusions”
Communicate results
Communicate Results:
- Write Science journal articles
- Speak at science conferences
- Exchange information on the Internet
Is an explanation observations or events that is based on prior knowledge gained from many observations and investigations. A —- does not develop from just one hypothesis, but from many hypotheses that are connected by a common idea.
A scientific theory
Is a rule that describes a repeatable pattern in nature. But it does not explain why or how the pattern happens, it only states with at it will happen. The law of conversation of energy is a —-.
A scientific law
Ask questions:
Make observations
State a problem
Gather information
Infer
What are the three branches of Science?
Physical Science
Earth Scientists
Life Scientists
The study of all of organisms and the many processes that occur in them.
Life Science
The many processes that occur on Earth and deep within Earth.
Earth Science
The study of matter and energy
Physical science, or physics and chemistry
