Tales by Dots and Lines Class 8 Long Question Answer

Tales by Dots and Lines Class 8 Long Question Answer

Tales by Dots and Lines Class 8 Long Question Answer

Question 1.

A courier-person cycles from a town to a neighbouring suburban area to deliver a parcel to a merchant. His distance from the town at different times is shown by the following graph :

(a) What is the scale taken for the time axis ?

(b) How much time did the person take for the travel ?

(c) How far is the place of the merchant from the town ?

(d) Did the person stop on his way ? Explain.

(e) During which period did he ride fastest ?

Solution:

In the graph, we find that the time is represented on the x-axis and the distance (in km) is represented on the y-axis. The distance at any time can be read from the graph exactly in the same way as we read the coordinates of a point. From the graph, we observe that :

(a) The scale taken for the time axis is : 4 units = 1 hour.

(b) The person took 3[latex]\frac{1}{2}[/latex] hours for the travel.

(c) The merchant’s place from the town is 22 km.

(d) Yes; this is indicated by the horizontal part of the graph (10 a.m. - 10.30 a.m.)

(e) Between 8 a.m. and 9 a.m. he ride fastest.

Question 2.

Can there be a time-temperature graph as follows? Justify your answer.

Solution:

(i) This represents a time-temperature graph, because it represents a smooth rise in temperature and is represented by a line graph.

(ii) This represents a time-temeprature graph, because it represent a smooth fall in temeprature and is represented by a line graph.

(iii) This does not represent a time- temperature graph, because it shows different temperatures at the same time.

(iv) This represents a time-temperature graph, because it shows a constant temperature at different times and is a line graph.