UNIT ONE: MOTION IN A STRAIGHT LINE Flashcards
What is displacement?
Displacement is change in position and is a vector quantity.
What is motion?
Motion is change in an object’s location as measured by the observer
What is distance?
The total length of the path travelled by an object in motion. It is a scalar quantity.
What is direction?
The line an object moves along from an origin point.
What is a scalar quantity?
Scalar quantities are measurements that only have a magnitude. Magnitudes represent size, not but directio.
What is a vector?
Vector is a quantity that has BOTH magnitude and direction.
What is position?
Position is the distance and direction of an object from a specific reference point. Position is a vector quantity.
What is this formula for?
displacement.
final position - initial position
When an object changes position more than once, the total displacement can be calculated how?
Adding the displacements together.
If you left home, travelled to school, then to work, what is your distance?
2000m
If you left home, went to school, the library, work and came home at the end of the day, what is your displacement?
displacement = final position - initial position
displacement is zero.
You ended where you started.
What is each line called?
a. line segment
b. directed line segment.
c. directed line segment.
Define average speed
Average speed (Vav) is the total distance travelled divided by the total time taken to travel that distance
ex. A car travelled 50km, and it took an hour to get to it’s destination.
50km divided by 60mins
= 50km/hour
What is average velocity?
Average velocity is the total change in position divided by the total time for that displacement.
A position-time graph describes the ________ of an object, with ______ on the vertical axis and _______ on the horizontal axis
A position-time graph describes the motion of an object, with position on the vertical axis and the time on the horizontal axis
The slope of a position-time graph gives us
the velocity of an object.
Which graph can determine the average velocity with the information it contains?
Position-time graph
Motion of an object at a constant speed AND in a straight line is called ____________
Motion of an object at a constant speed AND in a straight line is called motion with uniform / constant velocity
Motion in which the object’s speed changes or the object does not travel in a straight line is ______________
Motion in which the object’s speed changes or the object does not travel in a straight line is motion with non-uniform velocity (accelerated motion)
How would the position-time graph look, given the type of motion:
Given the type of motion, how would the position-time graph look?
Given the type of motion below, how would the graph look?
Given the type of motion, what does the position-time graph look like and what does it represent?
Constant positive velocity
Given the following types of motion, what does the position-time graph look like and what does it represent?
Straight line, represents constant velocity
How quickly the change in velocity of an object describes ______________
How quickly the change in velocity of an object describes acceleration.
A graph describing the motion of an object, with uniform velocity or uniform accerlation is called? What is on the vertical axis, what is on the horizontal axis?
A velocity-time graph with velocity on the vertical axis and time on the horizontal.
What are some characteristics of the type of motion this position-time graph?
- object is speeding up in a positive direction.
- it is not constant, shows acceleration
Is this object slowing down or speeding up? Is velocity constant?
It is speeding up in a negative direction (west) and the velocity is not constant since the line is curved showing change.
Is the object increasing in speed or slowing down? How do you know?
The object is slowing down, moving in a positive direction. It is slowing down because the slope of the curve is decreasing.
Given the motion type, what does the position-time graph look like?
The slope of a velocity-time graph gives the ____________ of the object.
The slope of a velocity-time graph gives the acceleration of the object.
The area under the velocity-time graph gives the ___________ of the object.
The area under the velocity-time graph gives the displacement of the object.
What does this equation describe?
Average acceleration
slope.
What is the SI unit for acceleration?
m/s2
Motion with uniform acceleration:
is motion in which velocity changes at a constant rate.
Instaneous velocity is the velocity of an object at a _____________ in time
Instaneous velocity is the velocity of an object at a specific instant in time
A graph describing motion of an object, with acceleration on the vertical axis and time on the horizontal axis is called:
an acceleration-time graph
image shows uniform acceleration
The area under an acceleration-time graph determines __________
The area under an acceleration-time graph determines change in velocity.
What type of motion do the three graphs represent?
uniform acceleration.
How do you create a velocity-time graph from an acceleration-time graph?
- calulate area under the curve, break it into different sections where necessary
- plot points onto chart at various points in time
- plot data to create the velocity-time graph.
How do you create an acceleration-time graph from a velocity-time graph?
- calculate slope of the line to find acceleration
- record the acceleration at different points in time
- use info to plot acceleration at various points in time on a-t graph
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