Page 120 - Ripples SCIENCE 7 - TEJPUR Edition 2024 Answer Key

∴ 15 = Distance
6

or Distance = 15 × 6 = 90 km.

4. A man runs 10 km in 30 min. What is his speed in kilometre per hour?
Ans: Given – Distance covered by man = 10 km
Time taken by man = 30 minutes

1 30
= hour
2 60
= 0.5 hour.

We know that

Speed = Distance
Time

Speed = 100 = 20 km/h
0.5

Hence the speed in km/h is 20 km/h
5. With what speed should a car travel so that it can cover a distance of 10 km in 5

minutes?
Ans: Given - Distance = 10 km

Time = 5 mintes = 5 hour
60
/
Speed = Distance = 10 5
Time 60
12
or Speed = 10 × 60
5 1
or Speed = 120 km/h.
6. A train is travelling at a speed of 100 km/h. How long will it take to complete a journey

of 500 km without stopping in between?

Ans: Given- Speed of train = 100 km/h
Distance covered by train = 500 km
Time taken = ?

We know that

Speed = Distance
Time

or 100 = 500
Time

or Time = 500 5
100 1
or Time = 5 hour.

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