Q81 of 90 Page 372

As part of his science project, Prithvi was supposed to record the temperature every hour one Saturday from 6 am to midnight. At noon, he was taking lunch and forgot again. He recorded the data so collected on a graph sheet as shown below.


A) Why does it make sense to connect the points in this situation?


B) Describe the overall trend, or pattern, in the way the temperature changes over the time period shown on the graph.


C) Estimate the temperature at noon and 8 pm.

A) To observe change in the data over a period of time, we plot a graph and join the points.


B) We can see from the graph that temperature increases from 8°C at 6 am to 21°C at 1 pm (between 12 noon and 2 pm, we can say that temperature is approximately 21°C) and then it decreases to around 9°C at 9 pm(between 8 pm and 10 pm in the graph). It remains constant for an hour (9 pm to 10 pm) and then decreases. We observe that at 12 pm the temperature is 8°C, same as it was at 6 am. Thus, we see that temperature first increases and then decreases from 6 am to 12 pm.


C) On looking carefully at the graph, we see that temperature is around 17°C at 11 am and thus, it is 19°C at 12 noon.


At 8 pm temperature is 10°C.


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(b) Use your graph to predict the outputs for inputs of 3 and 8.

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This graph shows a map of an island just off the coast of a continent. The point labelled B represents a major city on the coast. The distance between grid lines represents 1 km.


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(iii) Which point is in the water, (2, 7) or (7, 2)? Mark the point which is in water on your map and label it E.


(iv) Give the coordinates of two points on the island that are exactly 2 km from Point A.


(v) Give the coordinates of the point that is halfway between Points L and P.


(vi) List three points on the island with their x-coordinates greater than 8.


(vii) List three points on the island with a y-coordinate less than 4.

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The graph given below compares the price (in Rs) and weight of 6 bags (in kg) of sugar of different brands A, B, C D, E, F.


A) Which brand(s) costs/cost more than Brand D?


B) Bag of which brand of sugar is the heaviest?


C) Which brands weigh the same?


D) Which brands are heavier than brand B?


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The points on the graph below represent the height and weight of the donkey, dog, crocodile, and ostrich shown in the drawing.


A) What are the two variables represented in the graph?


B) Which point represents each animals? Explain.