The presentation is meant for secondary level physics students

1. Physics for secondary or O-level classes

2. Distance-Time and speed-time
Graphs: What?
 Instead of describing motion of an object in
words, it can be described by the distance-
time and speed-time graphs
 Students are required to draw and read
graphs and so are the scientists
 For a distance-time graph: Convention is...
 Time is taken along X-Axis
 Distance or speed is taken along Y-Axis

3. A typical distance-time graph
A typical graph Some interpreting hints
 Slopes of the various parts of the
graph tell how the speed is
changing
 Slope-up = speed is increasing
 Slope-down = speed is
decreasing
 Flat-graph = steady speed
 Steep slope: fast change in speed
 Gentle slope: slow change in
speed

4. PLOTTING THE GRAPH FROM DATA: JOURNEY
FROM DELHI TO CHANDIGARH
Plotted graph from data
Data from graph of journey
for Delhi to Chandigarh
City Distance
/km
Time / hr
Delhi 0 0
Panipat 60 1
Kurukshetra 120 2
Ambala 180 3
Chandigarh 240 4

5. Describing inter-city journey
speed-time graph
Distance- time graph Journey by inter-city train
A= Speeding up
B= Steady speed
C= Slowing down
D= Stoppage or
zero speed

6. Interpreting speed-time graph
Given speed time graph
Interpreting and naming
various sections of the graph
 A & G = Steady speed
 B & D = Slowing down
 E = Zero speed or being
stationary
 F = Speeding up

7. Area under speed-time graph is
distance moved
 We now understand that the motion of an objects can
be described through speed-time graph
 Speed-time graph can be used to find how much the
object has moved
 Equation / formula is:
Distance = Area under speed-time graph

8. Area under flat and sloped graph
Area under flat graph=
Rectangle or square
Area under sloped graph:
Triangle

9. Area under mixed graphs
Flat + sloped graph Three times sloped graph

10. Conclusions
Distance-time graph slopes
tell..
Speed-time graph: The area under
the graph is the distance covered
 Up-slope =Speeding up
 Down slope = Slowing down
 Zero slope / flat = Being
stationary
 Rectangular area =
length X Breadth
 Triangular area =
½ (Base X Height)
 Mixed area: Areas under
various graph sections are added
up