�NAVODAYA VIDYALAYA SAMITI�(An Autonomous Body Under MHRD) Government Of India �
Presents
E-Content for Class VII (Science)
Chapter 13
MOTION AND TIME
-Developed by
Mr. Vinod Kumar
T.G.T. Science
J. N. V. Dibrugarh, Assam
Learning Objectives-
1. Knowledge of graphs and its types
2.Understanding of graphs of uniform and non-uniform motions
3.Applying the skills to plot different distance-time relationships on graph
4.Interpretation of different shapes of distance time graphs
Previous Knowledge-
Knowledge of motion, types of motion and
speed
Distance-Time Graph �
The graph shows relationship between two Group
of measurements (or quantities). Three common
Graphs are-
1.Bar graph – Relationship in form of vertical pillars
2.Pie Chart –A division of whole
3.Line Graph-They show relationships in form of a line. The distance-time graphs are line graphs.
�Example� A bus starts journey at 2 P.M. and covers a distance of 80 Km in 2 Hour�at constant speed. �
S.N. | Time (In Per Half hour) | Distance (In Km) |
1 | 2:00 PM | 00 Km |
2 | 2:30 PM | 20 Km |
3 | 3:00 PM | 40 Km |
4 | 3:30 PM | 60 Km |
5 | 4:00 PM | 80 Km |
The line graph will be-
There are basic types of line graphs in four situations-
(c) Acceleration (d) Retardation
(De- acceleration)
Their line graphs are-
Points to remember
* Graphs show a correlation between two set of data.
* Distance time graphs show the motion of object. For an object moving with constant speed the distance time graph will be a straight line.
* The object moving with non-uniform speed like increased speed (acceleration) or decreased speed (retardation) then distance time graph will not be straight.
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