Page 219 - Maths Skills - 8

Introduction to Graphs 217

Let’s Attempt

Example 1: Observe the following graph carefully
and answer the given questions:
(i) What is the speed of the object at
20th second?
(ii) Calculate the speed of the object
during 0 – 40 seconds.
Solution: (i) Speed of the object at 20th second

= Distance travelled
Time taken

= 14 = 0.7 m/s
20
(ii) Speed during 0 – 40 seconds

= Distance travelled
Time taken
= 28 = 0.7 m/s
40

Exercise 13.3

1. The growth of a plant was recorded as a graph
shown below.
Read it carefully and find.

(i) At the end of which week(s) was the plant’s
height not more than 12 cm?

(ii) Between which two weeks was there the greatest
increase in height?
(iii) How much did the plant grow from 3rd week to
4th week?

2. A distance-time table of a moving car is given below.
Time 10:20 a.m. 10:30 a.m. 10:40 a.m. 10:50 a.m. 11:00 a.m. 11:10 a.m. 11:20 a.m.

Distance (in km) 0 5 12 22 26 28 38

(i) Using graph paper, plot the graph of distance versus time.
(ii) When was the car travelling at the greatest speed?