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Question
The graph given alongside shows how the speed of a car changes with time:
(i) What is the initial speed of the car ?
(ii) What is the maximum speed attained by the car ?
(iii) Which part of the graph shows zero acceleration ?
(iv) Which part of the graph shows varying retardation ?
(v) Find the distance travelled in first 8 hours.
Solution
(i) Initial speed of the car is 10 km/h
(ii) Maximum speed attained by the car is 35km/h
(iii) BC represents zero acceleration.
(iv) CD represents varying retardation.
(v) Distance travelled is given by the area enclosed within the curve. So,
Distance travelled = Area or trapezium + Area of rectangle
So distance travelled,
= (1/2)(8+5)(25) + (8)(10)
= 242.5 km
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