Position-Time Graph

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Name: _______________________________ Grade: 10 B1 B2
Please circle your section
Date: ___NOV 2017
Sayel Abu Alrob
PHYSICS DEPARTMENT
Grade 10 Physics Teaching Notes #3 Position-Time Graph
Term 1
Representing Motion
Position-Time Graph
How Fast
MAIN IDEA
You can use position-time graphs to determine an object’s position at a
certain time.
Objectives Checklist:

Practice the plotting of position-time graph

Read and analyze the position time graph

Compare the motion of two objects in position-time graph

Calculate the slope of position time graph

Identify the instantaneous velocity from the graph
Reference to the book:

Review page # ……… for the topic
Teaching notes for grade 10
P a g e |1
A. Position-Time Graph



To represent motion you can use motion diagram, tables and Graphs
Representing motion by graph: The motion of an object can be represented by a graph.
The graph is a pictorial representation of change of one physical quantity with respect to
the other.
In a position-time graph the two quantities are `position` and `time` in which the time is
always plotted on x-axis and position on y-axis.
B. Plotting Position Time Graph

The data listed in Table 1 can be presented on a position-time graph, in which the time
data is plotted on a horizontal axis and the position data is plotted on a vertical axis. To
draw this graph, first plot the runner's positions. Then, join these points by drawing a
straight lines that best fits the points.
 Sample 1 plotting:
X =0m
i
X = ……m
f
2
C. Reading Position Time Graph. Part (1)
 The data plotted in graph can be presented on a position-time table.
 Initial and final position can be determined also form the graph.
 Sample 2 Plotting: Label the X- axis and Y- axis, the Use this table to plot the points on
the graph and join these points by drawing a straight line.
X = ______________________
i
X = ______________________
f
 Sample 3 Reading graph: Complete the table of position-time for each graph and find
Xi and Xf.

3
X = ______________________
i
X = ______________________
f

ACTIVITY: Q1: Consider a man riding on a bicycle. The table below shows his
position at different times. Label the X- axis and Y- axis, the Use this table to plot the
points on the graph and join these points by drawing a straight line
X = ______________________
i
X = ______________________
f

4
Q2: Complete the table of position-time for each graph and find Xi and Xf
D. Reading Position Time Graph. Part (2)




From Position Time Graph, you can:
Determine the instantaneous position of the object at specific time or determine the time
taken to reach at specific position
Predict the expected positions or time intervals according to the pattern of the linear
graph.
Find total distance and total displacement.
 Sample 1: Refer to the diagram below to answer questions.
1. What is the position of the object at 3 s?
____________
2. How much time has passed when the
object is at 2 m?
________________
3. If the object continues at this speed,
when will the object reach 40 m?
_____________
4. If the object continues at this speed,
where will the object reach at 10 s?
___________
 Sample 2: Find the total distance and total displacement from the graph:
5
A.
Total distance: ______________
B.
Total displacement: _____________________
ACTIVITY 2:
Student A:
Student B:
Find the total distance and total displacement
from the graph.
Find the total distance and total displacement
from the graph.
Total distance: _______________________
Total distance: _______________________
Total displacement: ____________________
Total displacement: ____________________
E. Slope of Position Time Graph:



The slope of a line is the ratio of the “rise” (vertical
change) to the “run” (horizontal change) of the line.
In a position time graph the slope of the line is average
velocity ( ). Slope is the rise/run of a line.
The motion of more than one object can be graphed on
a single position-time graph.
=
6
E.1: Interpreting Position-Time graph
1. Steepness of slope on Position-Time graph:



The steepness of a line on a graph is called slop
Steep slope = higher velocity
Shallow slope = less velocity
E
2. Positive and negative (Slope) velocity
 The motion of an object can be expressed as moving with positive velocity, negative
velocity or at rest. Consider the example of a moving car.
A. This car is moving towards right or
east, it has positive velocity.
B. This car is moving towards left or west, it has
___________________.
C. This car is at rest. It has ___________. No
change in the position
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3. Intersection on Position vs time: Intersection in Position vs time indicates that the two
objects share the same position at that instant in time, Ex: Overtaking cars.
 Sample 1: Two drivers (driver A and driver B) are traveling in opposite directions on a
long, straight road. Their motions are represented by the position-time graphs of each,
shown below.
I.
II.
III.
IV.
8
How long had driver A already been driving when
driver B started to drive? __________
How long had driver A been driving when she was 30
km away from her starting point? __________
Which driver is faster? _________
What happens at point? __________

ACTIVITY 1: Three friends run a race. The graph below describes their motion
A. Who runs at the slowest velocity?
________________________
B. Who runs at the fastest velocity?
________________________
C. Who is at rest?
________________________
D. What happens at point I and M?
________________________
E. Who passes B path first and when?
________________________
F. Who travels the farthest after 40 s?
________________________
M
I
E.2 : Solving for slope = Average velocity

Recall: In a position time graph the slope of the line is average velocity ( ). Slope is the
rise/run of a line.
 Sample 1:
1. Solve the slope of A.
2.
3.
4.
5.
6.
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______________________________________________________________________________
Solve the slope of B.
______________________________________________________________________________
Solve the slope of C, Describe its motion.
______________________________________________________________________________
Solve the slope of D.
______________________________________________________________________________
Based on the slope, at which time it is moving the fastest? _______________________________
Based on the slope, at which time it is at rest? ________________________________________
ACTIVITY 2:
Student A:
Student B:
1.) Solve the slope of A and C. Which one is
faster?
2.) Solve the slope of E and H. Which one is
faster?
3.) Solve for B and F. Describe the motion for
both.
4.) Solve for D and G. Describe the motion for
both.
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