Page 119 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

C. Long-answer questions.

1. What is a graph? Explain the distance-time graph with an example.
Ans: Graph- A graph is a picture or a diagram that shows the relationship between two

or more variable quantities. This pictorial representation helps in easy and instant
interpretation of data and also in drawing comparisons between different quantities.

Distance-Time graphs- A distance-time graph is a type of line graph in which time
is represented on the x-axis and the distance covered by the object is represented

on the y-axis. Hence, a distance-time graph represents the distance covered by an
object in a particular time.

x–axis
Time (in min) 1 2 3 4 5 6 7
y–axis
Distance (in km) 1 2 3 4 5 6 7

y
8
7
6
2 Distance (in km) 4
5

3

(2 min, 2 km)
1
(1 min, 1 km)
0 x
0 1 2 3 4 5 6 7
Time (in min)
Line graph
2. A child is on a see-saw. What kind of motion does he have and why? Explain.
Ans: When children sit on a see-saw they experience oscillatory motion This means the

see-saw swings back & forth around its pivot. As one side goes up, the other side goes
down and then they switch places. This continues as the children keep on pushing
their feet.

Their motion is called oscillatory because it repeats in a regular pattern, moving
between two positions around the pivot point.
3. If a car is moving with a speed of 15 km/h on a highway, find the distance travelled

by the car in 6 h.
Ans: Given - Speed of the car = 15 km/h

Time taken = 6 h
We know that

Speed = Distance
Time

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